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Indicated Operations - Order of Operations

by Lisa
(NJ)











































Perform the indicated operations:

-42÷6+(-7

Which operation should be completed first?

Divide -42 by 6 first, and then add the -7; or, add the 6 and the -7 first, and then divide the -42 by -1?

Comments for Indicated Operations - Order of Operations

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May 04, 2011
Indicated Operations - Order of Operations
by: Staff


The question:

by Lisa
(NJ)

Perform the indicated operations:
-42÷6+(-7

The answer:

I added a right parenthesis

-42÷6+(-7)

For your information, the answer is -14.


The question in your mind is: which operation should I complete first? Should I divide -42 by 6 first, and then add the -7; or, should I add the 6 and the -7 first, and then divide the -42 by -1?


To simplify this expression:

1. IMPORTANT – This is the key: Read the expression from LEFT to RIGHT

-42÷6+(-7)

(-42÷6)+(-7)

2. use the PEMDAS order of operations.

To continue the simplification process, use the PEMDAS order of operations.

PEMDAS order tells you what to do first, second, . . . etc.

PEMDAS stands for: parentheses, exponents, multiplication, division, addition, subtraction


Step 1: evaluate PARENTHESES

PEMDAS order of evaluation: PARENTHESES, exponents, multiplication, division, addition, subtraction

There are two expressions enclosed in parentheses

(-42÷6) = -7
(-7) = -7

Step 2: evaluate EXPONENTS


PEMDAS order of evaluation: parentheses, EXPONENTS, multiplication, division, addition, subtraction

There are no exponents to evaluate.


Step 3: MULTIPLICATION


PEMDAS order of evaluation: parentheses, exponents, MULTIPLICATION, division, addition, subtraction

There is no multiplication to evaluate.


Step 4: DIVISION


PEMDAS order of evaluation: parentheses, exponents, multiplication, DIVISION, addition, subtraction

There are no parts of your expression which require any further division. The only division in the problem was within the first parentheses.


Step 5: evaluate ADDITION & SUBTRACTION

PEMDAS order of evaluation: parentheses, exponents, multiplication, division, ADDITION, SUBTRACTION

(-42÷6) + (-7)

= -7 + (-7)

= -7 - 7

= -14



The final answer is: -14



This problem illustrates how important it is to include parentheses to clarify the order of operations.


To ensure every reader understands the expression, it should have been written

(-42÷6) + (-7) = ?

Instead of

-42÷6+(-7) = ?




Thanks for writing.


Staff
www.solving-math-problems.com


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