(x+y+z)²-（x-y-z)²a(x-y)-x+yx²（a-b)+4(b-a)1.22²×9-1.33²×4共4题，

Question

(x+y+z)²-（x-y-z)² a(x-y)-x+y x²（a-b)+4(b-a) 1.22²×9-1.33²×4
共4题，

Answer 1

(x+y+z)²-（x-y-z)²= [(x+y+z)+(x-y-z)][(x+y+z)-(x-y-z)]=4x(y+z)
a(x-y)-x+y=a(x-y)-(x-y)=(a-1)(x-y)
x²（a-b)+4(b-a)=x²(a-b)-4(a-b)=(x²-4)(a-b)=(x+2)(x-2)(a-b)
1.22²×9-1.33²×4=(1.22*3)²-(1.33*2)²=(3.66+2.66)(3.66-2.66)=6.32