（1）0.5a^2(x-2a)^2-0.25a(2a-x)^3
问题描述：
（1）0.5a^2(x-2a)^2-0.25a(2a-x)^3
(2)-0.25(2a-b)^2+4(a-0.5b)^2
(3）5(x-y)^3+10(y-x)^2
(4)2a(x-a)+4b（a-x)-6c(x-a)
(5)(x^2-6X)^2+18(x^2-6x)+81
答
1.0.5a^2(x-2a)^2-0.25a(2a-x)^3 =(x-2a)^2[0.5a^2+0.25a(x-2a)]=(x-2a)^2*0.25ax2.-0.25(2a-b)^2+4(a-0.5b)^2 =-0.25(2a-b)^2+(2a-b)^2=0.75(2a-b)^2 3.5(x-y)^3+10(y-x)^2 =(x-y)^2[5(x-y)+10]=5(x-y)^2(x-y+2) 4....