分解因式:-9x³ 18x²-9x-搜答案-智慧作业帮

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)

分解因式x²－9=

(x+3)(x-3)

=(x-3y)²-3(x-3y)=(x-3y)(x-3y-3)

（x-1）²-9=(x-1+3)(x-1-3)=(x+2)(x-4)

2xy+9-x^2-y^2=9-x^2-y^2+2xy=9-(x^2+y^2-2xy)=9-(x-y)^2=[3-(x-y)][3+(x-y)]=(3-x+y)(3+x-y)

原式=x^4-6x³+9-x²=(x²-3)²-x²=(x²+x-3)(x²-x-3)

分解因式：x²-9

x²-9=x²－3²=(x＋3)(x－3)(平方差公式)

分解因式9-x²

3+x再答：乘3-x

【不好意思,题目太难让我想了很久】储备知识：x^n-y^n=(x-y)【x^(n-1)+x^(n-2)y+x^(n-3)y²+……+x²y^(n-3)+xy^(n-2)+y^(n-

2x2-4x-9是2x^2-4x-9这样吗用公式法（或者配方法）配方法2x^2-4x-9=2(x^-2x+1)-11=[根号2（x-1)]^2-(根号11)^2=[根号2*（x-1)+根号11]*[根

分解因式:X²－9

分解因式 2x^2y^2-9

2x²y²-9=(√2xy)²-3²=(√2xy+3)(√2xy-3)

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)²-9(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

解法1：将常数项8拆成-1+9．原式=x3-9x-1+9=（x3-1）-9x+9=（x-1）（x2+x+1）-9（x-1）=（x-1）（x2+x-8）．解法2：将一次项-9x拆成-x-8x．原式=x3

9-x^2+2xy-y^2=9-(x-y)^2=[3-(x-y)][3+(x-y)]=(3-x+y)(3+x-y)

x^3-9x=x(x^2-9)——每项都提取一个“x”=x(x^2-3^2)——把“9”变成“3^2”,使其成为平方差公式=x(x+3)(x-3)——根据平方差公式的逆用公式得出最后结果

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

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)