Solve the following equation and check your results: 5x + 9 = 5 + 3x

Transpose 3x to LHS and 9 to RHS
5x - 3x = 5 - 9
2x = -4
x = -2
LHS → 5x + 9 → 5(-2) + 9 = -10 + 9 = -1
RHS → 5 + 3x = 5 + 3(-2) = 5 - 6 = -1
LHS = RHS
Hence proved