Question

x + 3 - 7x = - 40 + 7

.

Answer 1

x+3-7x= - 40+7
3 - 6x= - 40+7
3 - 6x = - 33
3 + 33 = 6x
36 = 6x 
6 = x

Answer 2

-6x=-43+7
-6x=-36
-x=-36/6
-x=-6 /-1
x=6