9(x-y)^2+42(x-y)+49 16(x+y)2+40(x+y)(x-y)+25(x-y)^2 你懂的……没分了
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9(x-y)^2+42(x-y)+49 16(x+y)2+40(x+y)(x-y)+25(x-y)^2 你懂的……没分了= =谅解..
9(x-y)^2+42(x-y)+49
=[3(x-y)]^2+2*3(x-y)*7+7^2
= [3(x-y)+7]^2
= (3x-3y+7)^2
16(x+y)2+40(x+y)(x-y)+25(x-y)^2
=[4(x+y)]^2+2*4(x+y)*5(x-y)+[5(x-y)]^2
=[4(x+y)+5(x-y)]^2
=(4x+4y+5x-5y)^2
=(9x-y)^2
=[3(x-y)]^2+2*3(x-y)*7+7^2
= [3(x-y)+7]^2
= (3x-3y+7)^2
16(x+y)2+40(x+y)(x-y)+25(x-y)^2
=[4(x+y)]^2+2*4(x+y)*5(x-y)+[5(x-y)]^2
=[4(x+y)+5(x-y)]^2
=(4x+4y+5x-5y)^2
=(9x-y)^2
1、x(x-y)(x+y)-x(x+y)^2
(1)(x^2/x)-y-x-y
【(x-y)^2+(x+y)(x-y)】除以 2x
{(z+y)(x-y)-(x-y)的2次方+2y(x-y)}除以4y
(x+y)^2-16(x-y)^2
{(x,y) |x|+|y|
x>y?x:y
[(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y
x^2-y^2/x+y-4x(x-y)+y^2/2x-y,
(x+y)^2(x-y)^2-(x-y)(x+y)(x^2+y^2)分解因式
化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方
【x-3y][x+y]-[x-2y][x +2y]-[x-y