Common Core: High School - Algebra : Arithmetic with Polynomials & Rational Expressions

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All Common Core: High School - Algebra Resources

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Example Questions

Example Question #233 : High School: Algebra

Find the zeros of \(\displaystyle - 5 x^{2} + 36 x + 76\)

Possible Answers:

\(\displaystyle -36 , 36\)

There are no real roots

\(\displaystyle \frac{18}{5} + \frac{8 \sqrt{11}}{5} , - \frac{8 \sqrt{11}}{5} + \frac{18}{5}\)

\(\displaystyle 0\)

\(\displaystyle 16 \sqrt{11} , - 16 \sqrt{11}\)

Correct answer:

\(\displaystyle \frac{18}{5} + \frac{8 \sqrt{11}}{5} , - \frac{8 \sqrt{11}}{5} + \frac{18}{5}\)

Explanation:

In order to find the zeros, we can use the quadratic formula.

Recall the quadratic formula.

\(\displaystyle x =\frac{ - b \pm \sqrt{- 4 a c + b^{2}} }{ 2 a }\)

Where \(\displaystyle \uptext{a}\), \(\displaystyle \uptext{b}\), and \(\displaystyle \uptext{c}\), correspond to the coefficients in the equation

\(\displaystyle a x^{2} + b x + c = 0\)

In this case \(\displaystyle a = -5\)\(\displaystyle b = 36\) and \(\displaystyle c = 76\)

We plug in these values into the quadratic formula, and evaluate them.

\(\displaystyle x =\frac{ -36 \pm \sqrt{ 36 ^2 - 4 * -5 * 76 }}{ 2 * -5 }\)

\(\displaystyle x =\frac{ -36 \pm \sqrt{ 1296 - -1520 }}{ -10 }\)

\(\displaystyle x =\frac{ -36 \pm \sqrt{ 2816 }}{ -10 }\)


\(\displaystyle x =\frac{ -36 \pm 16 \sqrt{11} }{ -10 }\)

Now we split this up into two equations.

\(\displaystyle x =\frac{ -36 + 16 \sqrt{11} }{ -10 }\)

\(\displaystyle x =\frac{ -36 - 16 \sqrt{11} }{ -10 }\)

So our zeros are at

\(\displaystyle x = \frac{18}{5} + \frac{8 \sqrt{11}}{5}\)

\(\displaystyle x = - \frac{8 \sqrt{11}}{5} + \frac{18}{5}\)

Example Question #234 : High School: Algebra

Find the zeros of \(\displaystyle 4 x^{2} + 29 x + 19\)

Possible Answers:

\(\displaystyle \sqrt{537} , - \sqrt{537}\)

There are no real roots

\(\displaystyle - \frac{29}{8} - \frac{\sqrt{537}}{8} , - \frac{29}{8} + \frac{\sqrt{537}}{8}\)

\(\displaystyle 0\)

\(\displaystyle -29 , 29\)

Correct answer:

\(\displaystyle - \frac{29}{8} - \frac{\sqrt{537}}{8} , - \frac{29}{8} + \frac{\sqrt{537}}{8}\)

Explanation:

In order to find the zeros, we can use the quadratic formula.

Recall the quadratic formula.

\(\displaystyle x =\frac{ - b \pm \sqrt{- 4 a c + b^{2}} }{ 2 a }\)

Where \(\displaystyle \uptext{a}\), \(\displaystyle \uptext{b}\), and \(\displaystyle \uptext{c}\), correspond to the coefficients in the equation

\(\displaystyle a x^{2} + b x + c = 0\)

In this case \(\displaystyle a = 4\)\(\displaystyle b = 29\),  and \(\displaystyle c = 19\)

We plug in these values into the quadratic formula, and evaluate them.

\(\displaystyle x =\frac{ -29 \pm \sqrt{ 29 ^2 - 4 * 4 * 19 }}{ 2 * 4 }\)

\(\displaystyle x =\frac{ -29 \pm \sqrt{ 841 - 304 }}{ 8 }\)

\(\displaystyle x =\frac{ -29 \pm \sqrt{ 537 }}{ 8 }\)

\(\displaystyle x =\frac{ -29 \pm \sqrt{537} }{ 8 }\)

Now we split this up into two equations.

\(\displaystyle x =\frac{ -29 + \sqrt{537} }{ 8 }\)

\(\displaystyle x =\frac{ -29 - \sqrt{537} }{ 8 }\)

So our zeros are at

\(\displaystyle x = - \frac{29}{8} - \frac{\sqrt{537}}{8}\)

\(\displaystyle x = - \frac{29}{8} + \frac{\sqrt{537}}{8}\)

Example Question #235 : High School: Algebra

Find the zeros of \(\displaystyle x^{2} + 34 x + 24\)

Possible Answers:

\(\displaystyle -17 - \sqrt{265} , -17 + \sqrt{265}\)

\(\displaystyle -34 , 34\)

\(\displaystyle 2 \sqrt{265} , - 2 \sqrt{265}\)

\(\displaystyle 0\)

There are no real roots

Correct answer:

\(\displaystyle -17 - \sqrt{265} , -17 + \sqrt{265}\)

Explanation:

In order to find the zeros, we can use the quadratic formula.

Recall the quadratic formula.

\(\displaystyle x =\frac{ - b \pm \sqrt{- 4 a c + b^{2}} }{ 2 a }\)

Where \(\displaystyle \uptext{a}\), \(\displaystyle \uptext{b}\), and \(\displaystyle \uptext{c}\), correspond to the coefficients in the equation

\(\displaystyle a x^{2} + b x + c = 0\)

In this case \(\displaystyle a = 1\)\(\displaystyle b = 34\) and \(\displaystyle c = 24\)

We plug in these values into the quadratic formula, and evaluate them.

\(\displaystyle x =\frac{ -34 \pm \sqrt{ 34 ^2 - 4 * 1 * 24 }}{ 2 * 1 }\)

\(\displaystyle x =\frac{ -34 \pm \sqrt{ 1156 - 96 }}{ 2 }\)

\(\displaystyle x =\frac{ -34 \pm \sqrt{ 1060 }}{ 2 }\)

\(\displaystyle x =\frac{ -34 \pm 2 \sqrt{265} }{ 2 }\)

Now we split this up into two equations.

\(\displaystyle x =\frac{ -34 + 2 \sqrt{265} }{ 2 }\)

\(\displaystyle x =\frac{ -34 - 2 \sqrt{265} }{ 2 }\)

So our zeros are at

\(\displaystyle \\x = -17 - \sqrt{265} \\x = -17 + \sqrt{265}\)

Example Question #236 : High School: Algebra

Find the zeros of \(\displaystyle - 5 x^{2} + 30 x - 16\)

Possible Answers:

\(\displaystyle - \frac{\sqrt{145}}{5} + 3 , \frac{\sqrt{145}}{5} + 3\)

\(\displaystyle -30 , 30\)

\(\displaystyle 0\)

 There are no real roots

\(\displaystyle 2 \sqrt{145} , - 2 \sqrt{145}\)

Correct answer:

\(\displaystyle - \frac{\sqrt{145}}{5} + 3 , \frac{\sqrt{145}}{5} + 3\)

Explanation:

In order to find the zeros, we can use the quadratic formula.

Recall the quadratic formula.

\(\displaystyle x =\frac{ - b \pm \sqrt{- 4 a c + b^{2}} }{ 2 a }\)

Where \(\displaystyle \uptext{a}\), \(\displaystyle \uptext{b}\), and \(\displaystyle \uptext{c}\), correspond to the coefficients in the equation


\(\displaystyle a x^{2} + b x + c = 0\)

In this case \(\displaystyle a = -5\)\(\displaystyle b = 30\) and \(\displaystyle c = -16\)

We plug in these values into the quadratic formula, and evaluate them.

\(\displaystyle x =\frac{ -30 \pm \sqrt{ 30 ^2 - 4 * -5 * -16 }}{ 2 * -5 }\)

\(\displaystyle x =\frac{ -30 \pm \sqrt{ 900 - 320 }}{ -10 }\)

\(\displaystyle x =\frac{ -30 \pm \sqrt{ 580 }}{ -10 }\)

\(\displaystyle x =\frac{ -30 \pm 2 \sqrt{145} }{ -10 }\)

Now we split this up into two equations.

\(\displaystyle x =\frac{ -30 + 2 \sqrt{145} }{ -10 }\)

\(\displaystyle x =\frac{ -30 - 2 \sqrt{145} }{ -10 }\)

So our zeros are at

\(\displaystyle x = - \frac{\sqrt{145}}{5} + 3\)

\(\displaystyle x = \frac{\sqrt{145}}{5} + 3\)

Example Question #237 : High School: Algebra

Find the zeros of  \(\displaystyle - 3 x^{2} + 24 x + 87\)

Possible Answers:

\(\displaystyle 4 + 3 \sqrt{5} , - 3 \sqrt{5} + 4\)

\(\displaystyle -24 , 24\)

\(\displaystyle 0\)

\(\displaystyle 18 \sqrt{5} , - 18 \sqrt{5}\)

There are no real roots

Correct answer:

\(\displaystyle 4 + 3 \sqrt{5} , - 3 \sqrt{5} + 4\)

Explanation:

In order to find the zeros, we can use the quadratic formula.

Recall the quadratic formula.

\(\displaystyle x =\frac{ - b \pm \sqrt{- 4 a c + b^{2}} }{ 2 a }\)

Where \(\displaystyle \uptext{a}\), \(\displaystyle \uptext{b}\), and \(\displaystyle \uptext{c}\), correspond to the coefficients in the equation

\(\displaystyle a x^{2} + b x + c = 0\)

In this case \(\displaystyle a = -3\)\(\displaystyle b = 24\), and \(\displaystyle c = 87\)

We plug in these values into the quadratic formula, and evaluate them.

\(\displaystyle x =\frac{ -24 \pm \sqrt{ 24 ^2 - 4 * -3 * 87 }}{ 2 * -3 }\)

\(\displaystyle x =\frac{ -24 \pm \sqrt{ 576 - -1044 }}{ -6 }\)

\(\displaystyle x =\frac{ -24 \pm \sqrt{ 1620 }}{ -6 }\)


\(\displaystyle x =\frac{ -24 \pm 18 \sqrt{5} }{ -6 }\)


Now we split this up into two equations.

\(\displaystyle x =\frac{ -24 + 18 \sqrt{5} }{ -6 }\)

\(\displaystyle x =\frac{ -24 - 18 \sqrt{5} }{ -6 }\)

So our zeros are at


\(\displaystyle x = 4 + 3 \sqrt{5}\)

\(\displaystyle x = - 3 \sqrt{5} + 4\)

Example Question #238 : High School: Algebra

Find the zeros of \(\displaystyle - x^{2} + 18 x - 53\)

Possible Answers:

\(\displaystyle -18 , 18\)

\(\displaystyle - 2 \sqrt{7} + 9 , 2 \sqrt{7} + 9\)

There are no real roots

\(\displaystyle 0\)

\(\displaystyle 4 \sqrt{7} , - 4 \sqrt{7}\)

Correct answer:

\(\displaystyle - 2 \sqrt{7} + 9 , 2 \sqrt{7} + 9\)

Explanation:

In order to find the zeros, we can use the quadratic formula.

Recall the quadratic formula.

\(\displaystyle x =\frac{ - b \pm \sqrt{- 4 a c + b^{2}} }{ 2 a }\)

Where \(\displaystyle \uptext{a}\)\(\displaystyle \uptext{b}\), and \(\displaystyle \uptext{c}\), correspond to the coefficients in the equation

\(\displaystyle a x^{2} + b x + c = 0\)

In this case \(\displaystyle a = -1\), \(\displaystyle b = 18\), and \(\displaystyle c = -53\)

We plug in these values into the quadratic formula, and evaluate them.

\(\displaystyle x =\frac{ -18 \pm \sqrt{ 18 ^2 - 4 * -1 * -53 }}{ 2 * -1 }\)

\(\displaystyle x =\frac{ -18 \pm \sqrt{ 324 - 212 }}{ -2 }\)

\(\displaystyle x =\frac{ -18 \pm \sqrt{ 112 }}{ -2 }\)

\(\displaystyle x =\frac{ -18 \pm 4 \sqrt{7} }{ -2 }\)

Now we split this up into two equations.

\(\displaystyle x =\frac{ -18 + 4 \sqrt{7} }{ -2 }\)

\(\displaystyle x =\frac{ -18 - 4 \sqrt{7} }{ -2 }\)

So our zeros are at

\(\displaystyle x = - 2 \sqrt{7} + 9\)


\(\displaystyle x = 2 \sqrt{7} + 9\)

Example Question #239 : High School: Algebra

Find the zeros of \(\displaystyle - 7 x^{2} + 34 x + 16\)

Possible Answers:

There are no real roots

\(\displaystyle 2 \sqrt{401} , - 2 \sqrt{401}\)

\(\displaystyle \frac{17}{7} + \frac{\sqrt{401}}{7} , - \frac{\sqrt{401}}{7} + \frac{17}{7}\)

\(\displaystyle 0\)

\(\displaystyle -34 , 34\)

Correct answer:

\(\displaystyle \frac{17}{7} + \frac{\sqrt{401}}{7} , - \frac{\sqrt{401}}{7} + \frac{17}{7}\)

Explanation:

In order to find the zeros, we can use the quadratic formula.

Recall the quadratic formula.

\(\displaystyle x =\frac{ - b \pm \sqrt{- 4 a c + b^{2}} }{ 2 a }\)

Where \(\displaystyle \uptext{a}\), \(\displaystyle \uptext{b}\), and \(\displaystyle \uptext{c}\), correspond to the coefficients in the equation


\(\displaystyle a x^{2} + b x + c = 0\)

In this case \(\displaystyle a = -7\),  \(\displaystyle b = 34\),  and \(\displaystyle c = 16\)

We plug in these values into the quadratic formula, and evaluate them.

\(\displaystyle x =\frac{ -34 \pm \sqrt{ 34 ^2 - 4 * -7 * 16 }}{ 2 * -7 }\)

\(\displaystyle x =\frac{ -34 \pm \sqrt{ 1156 - -448 }}{ -14 }\)


\(\displaystyle x =\frac{ -34 \pm \sqrt{ 1604 }}{ -14 }\)

\(\displaystyle x =\frac{ -34 \pm 2 \sqrt{401} }{ -14 }\)

Now we split this up into two equations.

\(\displaystyle x =\frac{ -34 + 2 \sqrt{401} }{ -14 }\)

\(\displaystyle x =\frac{ -34 - 2 \sqrt{401} }{ -14 }\)

So our zeros are at

\(\displaystyle x = \frac{17}{7} + \frac{\sqrt{401}}{7}\)

\(\displaystyle x = - \frac{\sqrt{401}}{7} + \frac{17}{7}\)

Example Question #240 : High School: Algebra

Find the zeros of \(\displaystyle 5 x^{2} + 17 x - 21\)

Possible Answers:

\(\displaystyle \sqrt{709} , - \sqrt{709}\)

There are no real roots

\(\displaystyle - \frac{17}{10} + \frac{\sqrt{709}}{10} , - \frac{\sqrt{709}}{10} - \frac{17}{10}\)

\(\displaystyle 0\)

\(\displaystyle -17 , 17\)

Correct answer:

\(\displaystyle - \frac{17}{10} + \frac{\sqrt{709}}{10} , - \frac{\sqrt{709}}{10} - \frac{17}{10}\)

Explanation:

In order to find the zeros, we can use the quadratic formula.

Recall the quadratic formula.

\(\displaystyle x =\frac{ - b \pm \sqrt{- 4 a c + b^{2}} }{ 2 a }\)

Where \(\displaystyle \uptext{a}\), \(\displaystyle \uptext{b}\), and \(\displaystyle \uptext{c}\), correspond to the coefficients in the equation

\(\displaystyle a x^{2} + b x + c = 0\)

In this case \(\displaystyle a = 5\), \(\displaystyle b = 17\), and \(\displaystyle c = -21\).

We plug in these values into the quadratic formula, and evaluate them.

\(\displaystyle x =\frac{ -17 \pm \sqrt{ 17 ^2 - 4 * 5 * -21 }}{ 2 * 5 }\)

\(\displaystyle x =\frac{ -17 \pm \sqrt{ 289 - -420 }}{ 10 }\)

\(\displaystyle x =\frac{ -17 \pm \sqrt{ 709 }}{ 10 }\)

Now we split this up into two equations.

\(\displaystyle x =\frac{ -17 + \sqrt{709} }{ 10 }\)

\(\displaystyle x =\frac{ -17 - \sqrt{709} }{ 10 }\)

So our zeros are at

\(\displaystyle x = - \frac{17}{10} + \frac{\sqrt{709}}{10}\)

\(\displaystyle x = - \frac{\sqrt{709}}{10} - \frac{17}{10}\)

Example Question #21 : Identify Zeros, Factor And Graph Polynomials: Ccss.Math.Content.Hsa Apr.B.3

What are the \(\displaystyle x\)-intercept(s) of the function?

\(\displaystyle y=x^2+10x+25\)

Possible Answers:

\(\displaystyle \text{x-intercepts: }x=-5 \text{ and } x=5\)

\(\displaystyle \text{x-intercepts: }x=-5 \text{ and } x=0\)

\(\displaystyle \text{x-intercepts: }x=-5 \text{ and } x=-1\)

\(\displaystyle \text{x-intercept: }x=-5\)

\(\displaystyle \text{x-intercept: }x=5\)

Correct answer:

\(\displaystyle \text{x-intercept: }x=-5\)

Explanation:

To find the \(\displaystyle x\)-intercept of a function, first recall that the \(\displaystyle x\)-intercept represents the points where the graph of the function crosses the \(\displaystyle x\)-axis. In other words where the function has a \(\displaystyle y\) value equal to zero.

One technique that can be used is factorization. In general form,

\(\displaystyle y=x^2+bx+c\rightarrow(x+c_1)(x+c_2)\)

where,

\(\displaystyle c_1\) and \(\displaystyle c_2\) are factors of \(\displaystyle c\) and when added together results in \(\displaystyle b\).

For the given function,

 \(\displaystyle y=x^2+10x+25\)

the coefficients are,

\(\displaystyle \\b=10 \\c=25\)

therefore the factors of \(\displaystyle c\) that have a sum of \(\displaystyle b\) are,

\(\displaystyle y=(x+5)(x+5)\)

Now find the \(\displaystyle x\)-intercepts of the function by setting each binomial equal to zero and solving for \(\displaystyle x\).

\(\displaystyle \\x+5=0\rightarrow x=-5\)

To verify, graph the function.

Screen shot 2016 03 09 at 10.24.54 am

The graph crosses the \(\displaystyle x\)-axis at -5, thus verifying the result found by factorization. 

Example Question #1 : Polynomial Identities And Numerical Relationships: Ccss.Math.Content.Hsa Apr.C.4

Use FOIL for the following expression.

\(\displaystyle \left(a + 10 b\right)^{2}\)




Possible Answers:

\(\displaystyle a^{2}\)

\(\displaystyle b^{2}\)

\(\displaystyle 10 a b + 100 b^{2}\)

\(\displaystyle a^{2} + 20 a b + 100 b^{2}\)

\(\displaystyle a^{2} + 20 a b\)

Correct answer:

\(\displaystyle a^{2} + 20 a b + 100 b^{2}\)

Explanation:

The first step is to rewrite the problem as follows.


\(\displaystyle \left(a + 10 b\right)^{2} = \left( a + 10*b \right) \cdot \left( a + 10*b \right)\)

Now we multiply the first parts of the first and second expression together.

\(\displaystyle a \cdot a = a^{2}\)

Now we multiply the first term  of the first expression with the second term of the second expression.

\(\displaystyle a \cdot 10 b = 10 a b\)

Now we multiply the second term of the first expression with the first term of the second expression.


\(\displaystyle a \cdot 10 b = 10 a b\)

Now we multiply the last terms of each expression together.

\(\displaystyle 10 b \cdot 10 b = 100 b^{2}\)

Now we add all these results together, and we get.

\(\displaystyle a^{2} + 20 a b + 100 b^{2}\)




All Common Core: High School - Algebra Resources

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