Question

How do you evaluate the expression below when `-2x-8-(-3x+8)` when `x=3`?

Answer 1

• 13

Explanation:

the first thing to do is distribute the bracket and collect like
terms.

so - 2x - 8 + 3x - 8 = x - 16

x=3 : then x - 16 = 3 - 16 - -13

Here is a check doing it the 'long way'

x= 3 : -2(3) - 8 - (- 3(3) + 8 ) = -6 -8 -( - 9 + 8 )

= - 6 - 8 - (-9 + 8 ) = -6 - 8 - (-1) = -6 - 8 + 1 = - 13