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

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Answer 1 · 2016-07-27T16:16:02

See 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: $18-14=4$

Answer 2 · 2016-08-01T23:58:12

$16$

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

$color(red)(21-3)color(blue)(-(4+2))color(magenta)(+(3+5))$

$color(red)(18)color(blue)(-(6))color(magenta)(+8) =18-6+8$

Note that this is NOT! $" "18 - (6 +8)$

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

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

$18+8-6 = 16$

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