Algebra II : Solving Rational Expressions

Study concepts, example questions & explanations for Algebra II

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Example Questions

Example Question #4 : Multiplying And Dividing Rational Expressions

Simplify.

Possible Answers:

This expression cannot be simplified.

Correct answer:

Explanation:

a. Like when dividing fractions, change the division sign to multiplication and use the reciprocal of the divisor. 

b. Factor the trinomials in the numerator of both terms.

c. Cancel any common factors between the numerators and denominators.

This will leave: 

d. Multiply to simplify.

Example Question #5 : Multiplying And Dividing Rational Expressions

Expand:

Possible Answers:

Correct answer:

Explanation:

This problem will involve using the FOIL method to combine the first two parenthetical terms and then the distributive property to combine what is left. However, we can save time if we recognize that the first two parentheses are in form , with  and . We can therefore combine these two parentheses in form , and therefore:

Now we can use FOIL to find that:

which gives us a final answer of

Example Question #6 : Multiplying And Dividing Rational Expressions

Expand:

Possible Answers:

Correct answer:

Explanation:

To evaluate the expression, we will need to conduct the FOIL method on the first two polynomials and then use the distributive property to reach a final answer. Therefore:

which equals

Using the distributive property, we obtain:

which equals

Example Question #7 : Multiplying And Dividing Rational Expressions

Evaluate the following expression:

 

Possible Answers:

Correct answer:

Explanation:

To divide monomials, we subtract the exponents of the like terms. Therefore:

 

and 

Therefore:

Example Question #8 : Multiplying And Dividing Rational Expressions

Simplify:

Possible Answers:

Correct answer:

Explanation:

In order to solve this equation, we must first simplify it so that we can cancel common factors between the numerator and the denominator.

In the above equation, we can first factor a  from . This gives us:

This is easier for us to factor. In order to factor this, we need to see which factors of  have a sum of . This turns out to be  and . Therefore, we can simplify this expression into:

Next, we need to simplify .

This is a difference of perfect squares. Therefore, its factors are .

Now we need to simplify .

This is a perfect square trinomial. Therefore, this simplifies in the form . Note that this is negative since in order for the middle term to be negative, the sign of  must be negative as well.

Finally, we have to simplify .

To factor this, we need to see what multiples of  (the first term, , multiplied by the third term, ) have a sum of positive . This turns out to be positive  plus a negative . Since our first term is , we need to determine which of our factors is a multiple of . We can see that this is only , which means that our factors will be positive  and negative . Therefore, when we simplify our expression, we get a result of

Now our expression looks like

The  in the numerator cancels with the  in the denominator, the  in the numerator cancels with the  in the denominator, and one of the  factors in the numerator cancels with the  in the denominator. This gives us our solution of:

Example Question #1 : Multiplying And Dividing Rational Expressions

 

Find the remainder after dividing by this binomial.

Possible Answers:

Correct answer:

Explanation:

Either using synthetic division by 2 or using x=2 in the remainder theorem are 2 short-cuts to performing the long division of this polynomial.

Example Question #11 : Simplifying Expressions

For all values , which of the following is equivalent to the expression above?

Possible Answers:

Correct answer:

Explanation:

First, factor the numerator. We need factors that multiply to and add to .

We can plug the factored terms into the original expression.

Note that appears in both the numerator and the denominator. This allows us to cancel the terms.

This is our final answer.

Example Question #61 : Solving Rational Expressions

Simplify:

 

Possible Answers:

Correct answer:

Explanation:

The numerator is equivalent to

 

The denominator is equivalent to

 

 

Dividing the numerator by the denominator, one gets

Example Question #32 : How To Write Expressions And Equations

(9x2 – 1) / (3x – 1) = 

Possible Answers:

3x

(3x – 1)2

3x + 1

3

3x – 1

Correct answer:

3x + 1

Explanation:

It's much easier to use factoring and canceling than it is to use long division for this problem. 9x2 – 1 is a difference of squares. The difference of squares formula is a2 – b2 = (a + b)(a – b). So 9x2 – 1 = (3x + 1)(3x – 1). Putting the numerator and denominator together, (9x2 – 1) / (3x – 1) = (3x + 1)(3x – 1) / (3x – 1) = 3x + 1.

Example Question #21 : How To Divide Polynomials

Simplify:

 

 

Possible Answers:

None of the above

Correct answer:

Explanation:

Factor both the numerator and the denominator which gives us the following:

After cancelling we get

 

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