# How do you simplify (21-3)-(4+2)+(3+5) using PEMDAS?

Jul 27, 2016

See explanation

#### Explanation:

We must solve in the PEMDAS order. There are three sets of parentheses, so let's solve for those:

$21 - 3 = 18$
$4 + 2 = 6$
$3 + 5 = 8$

We now have $18 - 6 + 8$

There's no exponents, multiplication, or division. Next up is addition:
$6 + 8 = 14$

$18 - 14$

From here it's simple subtraction: $18 - 14 = 4$

Aug 1, 2016

$16$

#### Explanation:

There are 3 terms, each must simplify to a single answer which will be simplified in the LAST step.

$\textcolor{red}{21 - 3} \textcolor{b l u e}{- \left(4 + 2\right)} \textcolor{m a \ge n t a}{+ \left(3 + 5\right)}$

$\textcolor{red}{18} \textcolor{b l u e}{- \left(6\right)} \textcolor{m a \ge n t a}{+ 8} = 18 - 6 + 8$

Note that this is NOT! $\text{ } 18 - \left(6 + 8\right)$

We may not add in parentheses where we think they belong.

The additions are $+ 18 + 8$ and the subtraction is $- 6$

$18 + 8 - 6 = 16$