Answer:
a = 3
Step-by-step explanation:
Since x = 7 is a solution, substitute x = 7 into the equation and solve for a
4(7) - 2(7 + a) = 8 , that is
28 - 2(7 + a) = 8 ( subtract 28 from both sides )
- 2(7 + a) = - 20 ( divide both sides by - 2 )
7 + a = 10 ( subtract 7 from both sides )
a = 3
