Question

Mara simplifies the expression: -(7x - 3y) + 2(x + 4). Her work is shown. In what step does she make a mistake?

Answer 1

Correct steps are shown

Correct simplified expression is:

$-(7x - 3y) + 2(x+4) = -5x + 3y+8$

Solution:

Given that: Mara simplifies the expression

$-(7x - 3y) + 2(x+4)$

Correct steps are:

From given,

$-(7x - 3y) + 2(x+4)$

Use the distributive property,

a(b + c) = ab + bc

Therefore,

$-(7x - 3y) + 2(x+4) = -7x +3y + 2x + 8$

Group the like terms

$-(7x - 3y) + 2(x+4) = -7x + 2x + 3y + 8\\\\Combine\ the\ like\ terms\\\\-(7x - 3y) + 2(x+4) = -5x + 3y+8$

Thus the expression is simplified