If x = -2

(a) 3 (x + 5) - x - 7

will become

= 3 ( -2 + 5 ) - ( - 2 ) - 7

= 3 × 3 + 2 - 7

= 9 + 2 - 7

= 11 - 7 = 4

4 is the answer.

[tex] = 3 (x + 5) - x - 7 \\ \\ = 3( - 2 + 5) - ( - 2) - 7 \\ \\ = 3(3) + 2 - 7 \\ \\ = 9 - 5 \\ \\ = 4[/tex]