兽面纹代表什么:高手来啊!帮我做几道分解因式的题目吧!有高分!

来源:百度文库 编辑:高校问答 时间:2024/04/27 23:02:09
1.xy(x-y)-x(y-x)2 <2是平方>
2.64(x+y)2-72(x+y)(x-y) <(x+y)后面的2是平方>
3.7(a-3)-49(3-a)2 <2是平方>
请写出详细的步骤,谢谢,快,我很急,有高分悬赏!

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

64(x+y)^2-72(x+y)(x-y)
=8(x+y)(8x+8y-9x+9y)
=8(x+y)(17y-x)

7(a-3)-49(3-a)^2
=7(a-3)-7*7(a-3)(a-3)
=7(a-3)(1-7a+21)
=7(a-3)(22-7a)

1 =xy(x-y)+(x2-xy)(x-y)
=x2(x-y)
2 =(x+y)(64x+64y-72x+72y)
=(x+y)(136y-8x)
3 =(a-3)(7+49*2)
=105(a-3)