5*(c - 4) + x*(4 - c)
5*(c - 1*4) + x*(4 - c)
-20 + 5*c - x*(-4 + c)
-20 + 5*c - x*(-4 + c)
1*(c - 4)*(x - 5)
(1*(c - 4))*(x - 5)
-20 + 5*c + x*(4 - c)
-20 + 5*c + x*(4 - c)
-20 + 4*x + 5*c - c*x
-20 + 5*c + x*(4 - c)
-20 + 5*c + x*(4 - c)
-(-5 + x)*(-4 + c)
-(-5 + x)*(-4 + c)
-20 + 5*c + x*(4 - c)
-20 + 5*c + x*(4 - c)