作业帮2x³y 4x²y² 2xy³
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/15 23:52:06
解题思路：提取公因式进行分解解题过程：附件最终答案：略
3xy是3x原式=(x-3y)(x+2y)+3x+y+2十字相乘x-3y2×x+2y1所以原式=(x-3y+2)(x+2y+1)
对.前提是x不等于y
(x+y-2xy)(x+y-2)+(1-xy)^2=(x+y)^2-2(1+xy)(x+y)+4xy+1-2xy+x^2y^2=(x+y)^2-2(1+xy)(x+y)+(1+xy)^2=(x+y)^
3xy[2xy-x(y-2)+x-1]=3xy(2xy-xy+2x+x-1)=3xy(xy+3x-1)=3x^2y^2+9x^2y-3xy
3xy[2xy-x（y-2）+x]＝3xy[2xy-xy+2x+x]=3xy(xy+3x)=3x²y²+9x²y
(-3x^y+2xy)-(4x^+xy)=-3x^y+2xy-4x^-xy=-3x^y+xy-4x^所以填上-3x^y+xy-4x^
=xy(x-y)×[-xy/(x-y)]=-(xy)²=-x²y²
【x²+xy/（x-y）】/【xy/（x-y）】=【x²（x-y）/（x-y）+xy/（x-y）】/【xy/（x-y）】={【x²（x-y）+xy】/（x-y）}/【xy
（xy-y^2)÷x-y/xy=y(x-y)×[xy/(x-y)]=xy²
[(x²+2xy+y²)/(xy-y²)][(x²-2xy+y²)/(xy+y²)]={(x+y)²/[y(x-y)]}{(x-y
∴ 两直线交点(22/5,4/5)时,有最大值, （0,0）时,有最小值.
(x+y)(x-y)-x(y+1)-y(y+1)=(x+y)(x-y)-(x+y)(y+1)=(x+y)(x-2y-1)
同学,你打题有错误,但无所谓,这类题的解法是：将两条直线方程联立,解得交点坐标（用参数b表示的）,然后令横坐标再问：啊，抱歉啊，是打错了。y=-2x-4y=4x+b原题，呵呵不好意思。再答：我说的解题
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)
(x-y)/x²÷(x²-2xy+y²)/xy×(xy-x²)=(x-y)/x²÷(x+y)²/xy×x(y-x)=(x-y)²/
x^2y+4xy+4y=y(x²+4x+4)=y(x+2)²
原式=-x²y+2xy²+2x²y²-4xy³-3x³+27x³y-18x²y²+2x²y-18x&
解(x-y)/(xy-y²)=(x-y)/y(x-y)=1/y
利用公式法逆向因式分解(x+y)(x^2-xy+y^2)=x^3+y^3(x-y)(x^2+xy+y^3)=x^3-y^3都是公式可以自己乘开来试下可以抵消的（x^2-xy+y^2)和（x^2+xy+