logo for solving-math-problems.com
leftimage for solving-math-problems.com

Math - PEMDAS Order of Operations











































perform the following operations in the proper order. write your answer in simplest form 72 ÷ (-4) + 3(-4) / 5 – (-5)

Comments for Math - PEMDAS Order of Operations

Click here to add your own comments

Jul 27, 2011
PEMDAS Order of Operations
by: Staff


The question:

perform the following operations in the proper order. write your answer in simplest form 72 ÷ (-4) + 3(-4) / 5 - (-5)


The answer:


To simplify this expression:

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

72 ÷ (-4) + 3(-4) / 5 - (-5)

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 no expressions enclosed in parentheses


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

72 ÷ (-4) + 3(-4) / 5 - (-5)

There are two places where multiplication must be completed: 3(-4) and - (-5)


3(-4) = -12

- (-5) = +5

After completing the multiplication, the expression looks like this:


72 ÷ (-4) - 12/ 5 + 5



Step 4: DIVISION


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

There are two places where division must be completed: 72 ÷ (-4) and -12/ 5

72 ÷ (-4) = -18

-12/ 5 = -2.4

After completing the division, the expression looks like this:

-18 - 2.4 + 5


Step 5: evaluate ADDITION & SUBTRACTION

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

-18 - 2.4 + 5

= -15.4


The final answer is: -15.4




This problem also 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

[72 ÷ (-4)] + [3(-4) / 5] - (-5)

Instead of

72 ÷ (-4) + 3(-4) / 5 - (-5)




Thanks for writing.

Staff
www.solving-math-problems.com


Click here to add your own comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Math Questions & Comments - 01.



Copyright © 2008-2015. All rights reserved. Solving-Math-Problems.com