因式分解8[X平方减2Y平方]减X[7X加Y]加XY-搜答案-灵鹊做题网

1,（x+y）²-x²y²＝(x+y)²-(xy)²=(x+y+xy)(x+y-xy)2,-2a立方b平方+8a平方b平方-8ab平方=-2ab

3*((x-y/3+根号22/3*y)*(x-y/3-根号22/3*y))

可以使用平方差公式：m^2-n^2=(m+n)(m-n)所以(2x＋y)^2-(x+2y)^2=（2x＋y+x+2y)(2x＋y-x-2y）=(3x+3y)(x-y)=3(x+y)(x-y)

2x^2y^4-8x^4y^6=2x^2y^4(1-4x^2y^2)=2x^2y^4[1^2-(2xy)^2]=2x^2y^4(1+2xy)(1-2xy)

这个先提取公因式2 之后可以用平方差公式进行因式分解如图

(x-y)^2-8(x-y-2)=(x-y)^2-8(x-y)+16=[(x-y)-4]^2=(x-y-4)^2

(x-2y)³+8x²y-16xy=(x-2y)³+8xy(x-2y)=(x-2y)[(x-2y)²+8xy]=(x-2y)[x²-4xy+4y

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

(x+2y)的平方-4x的平方=(x+2y+2x)(x+2y-2x)=(3x+2y)(2y-x)

(a-b)+x平方(b-a)=(a-b)-x^2(a-b)=(a-b)(1-x^2)=(a-b)(1-x)(1+x)4M平方—（m+n)平方=(2m)^2-(m+n)^2=(2m-m-n)(2m+m+

原式=x^3+2x^2y+xy^2 =x(x^2+2xy+y^2) =x(x+y)^2再问：x-2��֮x-

x²-8xy+15y²+2x-6y=(x-3y)(x-5y)+2(x-3y)=(x-3y)(x-5y+2)

xy+y平方+x-y-2=xy+x+y^2-y-2=x(y+1)+(y+1)(y-2)=(y+1)(x+y-2)

2x²-8xy+8y²=2（x²-4xy+4y²）=2·【x²-2·x·（2y）+(2y)²】=2(x-2y)²再答：二十年教学经

x平方-8xy+16y平方-2x+8y-3=(x-4y)^2-2(x-4y)-3=(x-4y-3)(x-4y+1)

x的平方-2xy+y的平方-4=(x-y)²-2²=(x-y+2)(x-y-2)再问：(3a-7)的平方-(a+5)的平方这个呢？再答：(3a-7)的平方-(a+5)的平方=(3a

x平方-4y平方-x-2y=(x+2y)(x-2y)-(x+2y)=(x+2y)(x-2y-1)

原式＝（x+y）（x-y）

x平方-8y平方-2xy-2x+26y-15=(x+2y)(x-4y)-2x+26y-15=(x+2y)(x-4y)+3(x+2y)-5(x-4y+3)=(x+2y)(x-4y+3)-5(x-4y+3