Question 68216

Solution:
From the equation, f(x) = 4x - 3, Find f(-1). This shows that your x = -1 so what you are going to do is substitute -1 to x. so we will have 

f(-1) = 4(-1) -3
      = -4 -3
      = -7

therefore your f(x) = -7 if f(-1).

what if you have f(a-2), This shows that x = a-2 so substitute a-2 to x from the equation f(x) = 4x - 3

f(a-2) = 4(a-2) - 3   Distribution property
       = 4a - 8 - 3   Addition property
       = 4a - 11

therefore f(x) = 4a - 11 if f(a-2)