-y平方加9乘(x y的平方分解)
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x加y的平方等于9,x减y的平方等于5两式相减得:4xy=9-5=4xy=1
原等式可化为:x²-2xy+y²+6(x-y)+9+y²=0即:(x-y)²+6(x-y)+9+y²=0(x-y+3)²+y²=0
xy^2-2xy+2y-4=xy(y-2)+2(y-2)=(xy+2)(y-2)
x³-2x²y+xy²=x(x²-2xy+y²)=x(x-y)²
3x³-6x²y+3xy²=3x(x²-2xy+y²)=3x(x-y)²
3x^2+5xy-2y^2+x+9y-4=(3x-y)(x+2y)+4x+8y-3x+y-4={(3x-y)+4}(x+2y)-3x+y-4=(3x-y+4)(x+2y-1)
求根法:x^2+xy-2y^2+2x+7y-3=x^2+x(y+2)-2y^2+7y-3,△(x)=(y+2)^2-4(-2y^2+7y-3)=9y^2-24y+16=(3y-4)^2,x1=[-(y
X^2+Y^2=2XY=1/22X^2-Y^2-3XY-(X^2-2Y^2+XY)=2X^2-Y^2-3XY-X^2+2Y^2-XY=X^2+Y^2-4XY=2-4*1/2=2-2=0
6xy^2-9x^2y-y^3=-y(-6xy+9x^2+y^2)=-y(9x^2-6xy+y^2)=-y(3x-y)^2
xy(x-y)-x(x-y)平方=(x-y)[xy-x(x-y)]=(x-y)[2xy-x^2]=(x-y)*x(2x-y)-a平方+1.9b平方=(b根号1.9+a)(b根号1.9-a)-12xy+
=(3x)²-2*3x*2y+(2y)²=(3x-2y)²
1x²+2xy-3y²=x²+2xy+y²-4y²=(x+y)²-(2y)²=(x+y+2y)(x+y-2y)=(x+3y)(x-
xy²-2xy+2y-4原式=xy(y-2)+2(y-2)=(xy+2)(y-2)
解题思路:先将原式写为完全平方式,然后对照公式,即可分解。解题过程:
2x平方加4y平方加4XY等于(x+2y)(x+2y)的平方=100正负10的是100x+2y=10
3x²+5xy-2y²+x+9y-4=(3x-y)(x+2y)+x+9y-4=(3x-y+4)(x+2y-1)用二次十字相乘法:(1)3x²+5xy-2y²=(
(x-y+z)(x-y-z)
(1)3x²-4xy+6y²Δ=4²-4×3×6=16-72
∵x的平方加xy等于负5,xy加y的平方等于9∴x的平方减y的平方=(x²+xy)-(xy+y²)=-5-9=-142x的平方加3xy加y的平方=2(x²+xy)+(xy