20-9y-20y²等于零因式分解-搜答案-搜搜做题作业网

这是一个完全平方公式4(x+y)²－20(x+y)+25=[2(x+y)]²-2x5x2(x+y)+5²=[2(x+y)-5]²再问：能帮我讲解一下吗？再答：例

-y²/9-1+2y/3＝-（y²/9-2y/3+1）＝-(y/3-1)^2

解9(x-y)²-y²=[3(x-y)]²-y²=[3(x-y)-y][3(x-y)+y]=(3x-4y)(3x-2y)

y²-9(x+y)²=[y+3(x+y)][y-3(x+y)]=(y+3x+3y)(y-3x-3y)=-(3x+4y)(3x+2y)

1002x+2y+10

=(x-3y)²-3(x-3y)=(x-3y)(x-3y-3)

在实数范围内是没有解的只有在虚数范围内才有解（你确定?）再问：那用虚数怎么做呢再答：不用做了，考试一定不会出这种题的将x^2+25变成x^2-25就能做了（题目的可能写错了）5-x>0x

原式=24x+1+12²+4（x+y）²=【2²（x+y）²+12²】+24x+1=【2x+2y+12】²-48y-24x+1=【2x+2y

1-6y+y² 分解因式

1-6y+y²＝y²－6y＋9－8＝﹙y－3﹚²－8＝﹙y－3－2√2﹚﹙y－3＋2√2﹚.

9(x-y)^2+12(x^2-y^2)+4(x+y)^2=[3(x-y)]^2+2*3(x-y)*2(x+y)+[2(x+y)]^2=[3(x-y)+2(x+y)]^2=(5x-y)^2

(x+y)²-6x²+6y²+9(x-y)²=x²+2xy+y²-6x²+6y²+9x²-18xy+9y

原式=[3(x+y)]²-(x-y)²=[3(x+y)+(x-y)][3(x+y)-(x-y)]=(4x+2y)(2x+4y)=4(2x+y)(x+2y)

16(x-y)²+24(y²-x²)+9(x+y)²=[4(x-y)]²+2*4(x-y)*3(x+y)+[3(x+y)]²=[4(x-y)

16(x-y)²-9(x+y)²=【4（x-y）+3(x+y)】【4(x-y)-3(x+y)】=(7x-y)(x-7y)在我回答的右上角点击【评价】,然后就可以选择【满意,问题已经

(x+y)^4+(x+y)^2-20＝[﹙x＋y﹚²＋5﹚][﹙x＋y﹚²－4]＝﹙x²＋2xy＋y²＋5﹚﹙x＋y－2﹚﹙x＋y＋2﹚

4（x+y）²-20(x+y)+25=[2﹙x＋y﹚－5]²=﹙2x＋2y－5﹚²

:a(3x+9y)-x-3y=3a(x+3y)-(x+3y)=(3a-1))(x+3y)

4x^4y^2-5x^2y^2-9y^2=y^2(4x^4-5x^2-9)=y^2(4x^2-9)(x^2+1)=y^2(2x-3)(2x+3)(x^2+1)

16(X+Y)平方-9(Y-X)平方=[4(x+y)]²-[3(y-x)]²=[4x+4y-3y+3x][4x+4y+3y-3x]=(7x+y)(x+7y)