2 64 - 16*b + b
64 - 16*b + b^2 при b = 1/2
64 - 16*b + b^2
64 - 16*(1/2) + (1/2)^2
64 - 16/2 + (1/2)^2
225/4
2 64 + b - 16*b
64.0 + b^2 - 16.0*b
2 (-8 + b)