(y - 4)*2 - (4 - y)*(4 + y)
(y - 4)*2 - (4 - y)*(4 + y) при y = 4
((4) - 4)*2 - (4 - (4))*(4 + (4))
(4 - 4)*2 - (4 - 4)*(4 + 4)
0
-8 + 2*y - (4 + y)*(4 - y)
-8.0 + 2.0*y - (4.0 + y)*(4.0 - y)
2 -24 + y + 2*y
(-4 + y)*(6 + y)