Answer:
39
Step-by-step explanation:
4x+7=9x-33
4x-9x=-33-7
-5x=-40
x=8
4×8+7=39
402.12 + 804.24 = 1206.36
16x^2 + 9 = 25
16x^2 = 16
x^2 = 1
x = 1, -1
