Answer :
X=3.69. You first subtract 3.3 on both sides to get 7.5x by itself. Then divide and get x

Answer:
3.69
Step-by-step explanation:
7.5x + 3.3 = 31
7.5x = 31 - 3.3
7.5x = 27.7
x = 27.7 : 7.5
x = 3.69