For which equation is 7 a solution?
A3x + 1 = 27
B3(x + 1) = 24
C2x + 3(x-4) = 21
Dx2 - 8 = 42
A3x + 1 = 27
B3(x + 1) = 24
C2x + 3(x-4) = 21
Dx2 - 8 = 42