Question

计算(1).4ab-2a^2-2b (2).-8ax^2+16axy-8ay^2 (3).5.9^2-2*5.9*0.9

Answer 1

(1).4ab-2a^2-2b^2

=-2(a^2-2ab+b^2)

=-2(a-b)^2

(2).-8ax^2+16axy-8ay^2

=-8a(x^2-2xy+y^2)

=-8(x-y)^2

(3).5.9^2-2*5.9*0.9+0.9^2

=(5.9-0.9)^2

=5^2

=25