Can someone help me find the answer?

Answer:
a. x = 3/a
Step-by-step explanation:
Add all like terms on left hand side of the equation:
5 ax + 3 ax => 8 ax
Bring like term 4ax on left hand side
8ax - 4ax
=> 4ax
Therefore we get 4ax = 12
ax = 12/4
ax = 3
x = 3/a