(2а-3)^2-4а(а+1)= (2a-3)(2a-3)-4a(a+1) = (4a2-6a-6a+9)-4a(a+1) = 4a2-6a-6a+9-4a(a+1) = 4a2-6a-6a+9-4a2-4a = – 16a + 9
(2а-3)^2-4а(а+1)= (2a-3)(2a-3)-4a(a+1) = (4a2-6a-6a+9)-4a(a+1) = 4a2-6a-6a+9-4a(a+1) = 4a2-6a-6a+9-4a2-4a = – 16a + 9