x平方加xy加y方等于a方求面积-搜答案-拍题作业网

3x^2+2xy+y^2-6x-6y+9=0(x+y)^2-6(x+y)+9=0(x+y-3)^2=0x+y=3

x^2+y^2-4x-10y+29=0x^2-4x+4+y^2-10y+25=0(x-2)^2+(y-5)^2=0x=2y=5x^y+xy^2=xy(x+y)=2*5(2+5)=70

x²＋xy－2y²＝0﹙x－y﹚﹙x＋2y﹚＝0x＝y,x＝－2y当x＝y,﹙x²＋3xy＋y²﹚／﹙x²＋y²﹚=﹙y²＋3y&

已知x平方加xy等于8,y平方加xy等于9,则x平方加y平方加2xy值是8+9=17

√（x-4y）=4x-4y=4的2次方x-4y=16（1）（3x+5y）的3次方=-273x+5y=-3（2）（2）-（1）×3得3x+5y-3（x-4y）=-3-16×33x+5y-3x+12y=-

x³－2x²y＋xy²=x(x²－2xy＋y²)=x(x－y)²

∵x+y-4x+y+4+1/4=(x-4x+4)+(y+y+1/4)=(x-2)+(y+1/2)=0而要使两个非负数的和为0,那么这两个数均为0∴x-2=0,y+1/2=0∴x=2,y=-1/2∴原式

6,or-7二式相加,设u=x+y,u^2+u=42u=6,u=-7再问：什么是二式相加

x³+x²y+xy²+y³=x²(x+y)+y²(x+y)=(x+y)(x²+y²)

x²+2xy+4y²+x²y²+1=8xy(x²-4xy+4y²)+(x²y²-2xy+1)=0(x-2y)²

x+y=6xy=-21/x²+1/y²=(x²+y²)/(x²y²)=[(x+y)²-2xy]/(xy)²=(36+4)

先分解因式,后乘法.(X^4-Y^4)/(X^3+X^2Y+XY^2+Y^3)=(X-Y)(X+Y)(X^2+Y^2)/(X^3+X^2Y+XY^2+Y^3)=(X-Y)(X^3+X^2Y+XY^2+

x²＋xy＋y＝14①y²＋xy＋x＝22②①＋②得：﹙x＋y﹚²＋﹙x＋y﹚－36＝0x＋y＝﹙﹣1±√145﹚/2.再问：最后一步怎么得来的没有看懂再答：一元二次方程

解题思路：此题主要考查了完全平方公式的应用；解答时整体求解xy解题过程：解：∵x+y=6∴(x+y)2=36即：x2+2xy+y2=36∵x2+y2=12∴12+2xy=3

原式等于(xy)^2(x+y)将x+y=2,xy=4代入,得原式等于16×2=32

x^2+2xy+y^2=(x^2+xy)+(xy+y^2)=2+7=9

x^2+2xy+y^2=(x^2+xy)+(xy+y^2)=2+7=9

x³-y³-x²y+xy²=(x³-y³)-(x²y-xy²)=(x-y)(x²+xy+y²)-xy