# How do you simplify 7{ [3( b - 4) + 18] - [ 2( 5b - 2) + 3]}?

Apr 23, 2018

We always start from the inner parentheses to the outer ones:

$- 49 b + 49$

#### Explanation:

Let's start from the inner parentheses:

$3 \left(b - 4\right) = 3 b - 12$

$2 \left(5 b - 2\right) = 10 b - 4$

Next step:

$3 b - 12 + 18 = 3 b + 6$

$10 b - 4 + 3 = 10 b - 1$

Next:

$3 b + 6 - \left(10 b - 1\right)$

$= 3 b + 6 - 10 b + 1$

$= - 7 b + 7$

Then:

$7 \left(- 7 b + 7\right) = - 49 b + 49$