Algebra 1 : How to multiply integers

Study concepts, example questions & explanations for Algebra 1

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Example Questions

Example Question #75 : Integer Operations

Evaluate: \displaystyle \frac{(-6)^{2} + (-6)^{3} + 6^{4}}{6}

Possible Answers:

\displaystyle 216

\displaystyle 162

\displaystyle 258

\displaystyle 186

\displaystyle 174

Correct answer:

\displaystyle 186

Explanation:

\displaystyle \frac{(-6)^{2} + (-6)^{3} + 6^{4}}{6} =\frac{ 36 + (-216) + 1,296 }{6} = \frac{1,116}{6} = 186

Example Question #11 : How To Multiply Integers

Evaluate: \displaystyle \frac{7^{2} + (-7)^{3} + (-7)^{4}}{7}

Possible Answers:

\displaystyle 287

\displaystyle 399

\displaystyle 238

\displaystyle 350

\displaystyle 301

Correct answer:

\displaystyle 301

Explanation:

\displaystyle \frac{7^{2} + (-7)^{3} + (-7)^{4}}{7} =\frac{49 + (-343)+ 2401}{7} = \frac{2107}{7} = 301

Example Question #12 : How To Multiply Integers

Solve 

\displaystyle \left ( \frac{3}{4} \right)^{3}\times \left (\frac{2}{9}\right)^{2}

Possible Answers:

\displaystyle \frac{9}{432}

\displaystyle \frac{1}{48}

\displaystyle \frac{108}{5184}

\displaystyle \frac{3}{144}

\displaystyle \frac{18}{864}

Correct answer:

\displaystyle \frac{1}{48}

Explanation:

First, distribute the exponents to the numerators and denominators:

\displaystyle \frac{3^{3}}{4^{3}}\times\frac{2^{2}}{9^{2}}.

Then, rewrite the problem in expanded form:

\displaystyle \frac{3\cdot3\cdot3}{4\cdot4\cdot4}\times\frac{2\cdot2}{9\cdot9}

Next, rewrite the problem so that you only have prime factors in both numerators and denominators: 

\displaystyle \frac{3\cdot3\cdot3}{2\cdot2\cdot2\cdot2\cdot2\cdot2}\times\frac{2\cdot2}{3\cdot3\cdot3\cdot3}.

Last, simplify by "canceling out" like terms, leaving you with

\displaystyle \frac{1}{2\cdot2\cdot2\cdot2}\times\frac{1}{3}

and multiply across both numerators and denominators, which will give you \displaystyle \frac{1}{48}.

Example Question #13 : How To Multiply Integers

\displaystyle \sqrt2 \times \sqrt18

Possible Answers:

\displaystyle \sqrt20

\displaystyle 36

\displaystyle 2\sqrt18

\displaystyle 6

Correct answer:

\displaystyle 6

Explanation:

\displaystyle \: \sqrt2 \times \sqrt18 = \sqrt36 = 6

Example Question #14 : How To Multiply Integers

Multiply and express the product in scientific notation:

\displaystyle \left (5 \times 10^{20} \right ) \left (8\times 10^{9} \right )

Possible Answers:

\displaystyle 40 \times 10^{30}

\displaystyle 40 \times 10^{180}

\displaystyle 4 \times 10^{181}

\displaystyle 4 \times 10^{30}

\displaystyle 40 \times 10^{29}

Correct answer:

\displaystyle 4 \times 10^{30}

Explanation:

Use your power properties to multiply these numbers.

\displaystyle \left (5 \times 10^{20} \right ) \left (8\times 10^{9} \right )

\displaystyle =\left (5 \cdot 8 \right )\times \left (10^{20} \cdot 10^{9} \right )

\displaystyle =40 \times 10^{20+9}

\displaystyle =40 \times 10^{29}

This is not in scientific notation, so adjust as follows:

\displaystyle 40 \times 10^{29}

\displaystyle =4 \times 10^{1} \times 10^{29}

\displaystyle =4 \times 10^{1+29}

\displaystyle =4 \times 10^{30}

Example Question #15 : How To Multiply Integers

Multiply and express the product in scientific notation:

\displaystyle \left (9.2 \times 10^{12} \right ) \left (1.5\times 10^{12} \right )

Possible Answers:

\displaystyle 1.38 \times 10^{25}

\displaystyle 1.38 \times 10^{24}

\displaystyle 13.8 \times 10^{24}

\displaystyle 0.138 \times 10^{25}

\displaystyle 0.138 \times 10^{26}

Correct answer:

\displaystyle 1.38 \times 10^{25}

Explanation:

Use your power properties to multiply these numbers.

\displaystyle \left (9.2 \times 10^{12} \right ) \left (1.5\times 10^{12} \right )

\displaystyle =\left (9.2 \cdot 1.5 \right )\times \left (10^{12} \cdot 10^{12} \right )

\displaystyle =13.8 \times 10^{12+12}

\displaystyle =13.8 \times 10^{24}

This is not in scientific notation, so adjust as follows:

\displaystyle 13.8 \times 10^{24}

\displaystyle =1.38 \times 10^{1} \times 10^{24}

\displaystyle =1.38 \times 10^{1+24}

\displaystyle =1.38 \times 10^{25}

Example Question #16 : How To Multiply Integers

Rewrite as a number in base ten: \displaystyle 243_{\textrm{five}}

Possible Answers:

\displaystyle 55

\displaystyle 23

\displaystyle 97

\displaystyle 73

\displaystyle 37

Correct answer:

\displaystyle 73

Explanation:

\displaystyle 243_{\textrm{five}}

\displaystyle = 2 \cdot 5^{2} + 4 \cdot 5^{1 } + 3

\displaystyle = 2 \cdot 25 + 4 \cdot 5 + 3

\displaystyle = 50 +20+3 = 73

Example Question #17 : How To Multiply Integers

Rewrite as a number in base ten: \displaystyle 231_{\textrm{six}}

Possible Answers:

\displaystyle 72

\displaystyle 56

\displaystyle 26

\displaystyle 43

\displaystyle 91

Correct answer:

\displaystyle 91

Explanation:

\displaystyle 231_{\textrm{six}}

\displaystyle = 2 \cdot 6^{2} + 3 \cdot 6^{1} + 1

\displaystyle = 2 \cdot 36 + 3 \cdot 6 + 1

\displaystyle = 72+ 18+ 1 =91

 

Example Question #18 : How To Multiply Integers

Simplify the following:

\displaystyle 4+5*10^2-5

Possible Answers:

\displaystyle 99

\displaystyle 8095

\displaystyle 2499

\displaystyle 104

\displaystyle 499

Correct answer:

\displaystyle 499

Explanation:

In this problem, you need to use the proper order of operations to find the correct answer: PEMDAS (Parentheses, Exponents, Multiplication-Division, Addition-Subtraction).

Exponents show up first in this problem, so the first step is to simplify:

\displaystyle 10^2 = 100

This results in:

\displaystyle 4+5*100-5

The next step is the multiplication:

\displaystyle 5*100=500

This results in:

\displaystyle 4+500-5

The next step is to do the remaining addition and subtraction from left to right.

\displaystyle 4+500-5=499

499 is your final answer.

Example Question #1 : Elementary Operations

Evaluate the expression.

\displaystyle \small (3+4)^2+(\frac{3+5}{2})+6\div 2

Possible Answers:

\displaystyle 33

\displaystyle 29

\displaystyle 60

\displaystyle 56

Correct answer:

\displaystyle 56

Explanation:

Follow the correct order of operations: parenthenses, exponents, multiplication, division, addition, subtraction.

\displaystyle \small (3+4)^2+(\frac{3+5}{2})+6\div 2

First, evaluate any terms in parenthesis.

\displaystyle (7)^2+(\frac{8}{2})+6\div 2

\displaystyle 7^2+4+6\div 2

Next, evaluate the exponent.

\displaystyle \small 49+4+6\div2

Divide.

\displaystyle \small 49+4+3

Finally, add.

\displaystyle \small 49+4+3=56

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