# How do you simplify 9xx10+80-78-+17xx7 using the order of operations?

Feb 22, 2017

The answer is $- 27$.

#### Explanation:

Follow the order of operations as given in the acronym PEMDAS.

$\textcolor{red}{\text{P:}}$ parentheses or brackets
$\textcolor{b l u e}{\text{E:}}$ exponents or powers
$\textcolor{g r e e n}{\text{M:}}$ multiplication
$\textcolor{g r e e n}{\text{D:}}$ division

$\textcolor{p u r p \le}{\text{A:}}$ addition
$\textcolor{p u r p \le}{\text{S:}}$ subtraction

(M and D have equal weight and are calculated from left to right.)

(A and S have equal weight and are calculated from left to right.

Given:

$9 \times 10 + 80 - 78 - + 17 \times 7$

A negative and a positive make a negative.

$9 \times 10 + 80 - 78 - 17 \times 7$

Carry out the multiplications first.

$90 + 80 - 78 - 119$

Carry out the addition and subtraction from left to right.

$170 - 78 - 119$

$92 - 119$

$- 27$