If x = 12 is the solution of equation 5 (x + 4a) = 1 / 2 (X-2), then a =. The process of solving the equation

If x = 12 is the solution of equation 5 (x + 4a) = 1 / 2 (X-2), then a =. The process of solving the equation

Substituting x = 12 into equation 5 (x + 4a) = 1 / 2 (X-2)
60+20a=5 20a=-55 a= -2.75