3y-3=2y2

3y2(2y用整式分配率,分开成

(3y2-y)2=3(3y2-y)-2答案和解题过程一元二次方程(3y2-y)2-3(3y2-y)+2=0(3y2-y-2）(3y2-y-1）=0（3y+2）（y-1）（3y2-y-1）=0y=-2/3或y=1或3y2-y-1=0再公式法解

已知：x2-y2=16,x+y=2,求：3x-3y/y2-x2+x2-2xy+y2/x2-y2-x2-x-6/x+2除以(x+y)已知：x2-y2=16,x+y=2,求：（3x-3y）/（y2-x2）+（x2-2xy+y2）/（x2-y2）

已知|y/x|=3,求分式[(x2+2*x*y+y2)*(x-y)]/[x2*y2*(x-2*y)]的值条件有y2=9*x2原式=-8*（x＋y）／9＊x2*（x－2＊y）当3*x＝－y原式＝16／63＊x2当3*x＝y原式＝32／54＊x

先化简,再求值:2x2-y2+2y2-3x2-2y2+x,其中x=-1,y=22x2-y2+2y2-3x2-2y2+x=（2x2-3x2）+（-y2+2y2-2y2）+x=-x^2-y^2+x将x=-1,y=2带入得-1-4-1=-6原式=

我老妈狂骂...1.（y2-3y+2）（y2+3y-2)=y2(y+3)(y-3)2.(2x-1)(2x+1)+3(x+2)(x-2)=(7x-1)(x+1)3.兄弟二人养了一群羊，当每只羊的价钱（以元为单位）恰等于这群羊的只数时，将羊全部

如果2/x=3/y,那么x2-2xy+3y2/7x2-y2?2/x=3/y2y=3xy=3x/2代入x2-2xy+3y2/7x2-y2消去yx2-2xy+3y2/7x2-y2=x^2-3x^2+27x^2/4/7x^2-9x^2/4

若x2+y2-3y=0,求2x2-y2的取值范围x²>=0所以x²=-y²+3y>=0y(y-3)

先化简,再求值：9y+6y2-3（y-2/3y2）,其中y=-29y+6y2-3（y-2/3y2）=9y+6y²-3y+2y²=6y+8y²=6*（-2）+8*（-2）²=-12+32=20

已知9-6y-4y2=7,求2y2+3y+7的值.（y2代表y的平方）急!9-6y-4y2=7也就是说4y2+6y=2注意到4y2+6y=2(2y2+3y)=2即2y2+3y=1所以2y2+3y+7=81变型-4y2-6y=-2(4y2+6

-y2-2y+3=0配方法-y2-2y+3=0配方法y2+2y-3=0(y+3)(y-1)=0y=-3或者y=1无量寿佛,佛说苦海无涯回头是岸!施主,我看你骨骼清奇,器宇轩昂,且有慧根,乃是万中无一的武林奇才.潜心修习,将来必成大器,吾手中

解方程3/y-1+5y-2/y2-y=6/y两边乘以y(y-1)得3y+5y-2=6y-62y=-4y=-2检验：y=-2是方程的解

例;已知代数式9-6y-4y2=7,求2y2+3y+7的值.因此2y2+3y=1所以2y2+3y+7=8己知代数式14x+5-21x2=-9,求6x2-4x-5的值.14x+5-21x2=-914x-21x^2=-142x-3x^2=-23

(x2-y2)-4(2x2-3y)=x²-y²-8x²+12y=-7x²-y²+12y(x²-y²)-4(2x²-3y)=x²-y²-8x&

3y2-x2+(2x-y)-2(x2+3y2),其中x=1,y=-2先化简,再求值.3y2-x2+(2x-y)-2(x2+3y2)=3y^2-x^2+2x-y-2x^2-6y^2=-3x^2-3y^2+2x-y=-3-12+2+2=-11

X-2Y+Z=X2+Y2+Z2=2,求2(X2-Y2-2)-(2X-4Y-3Y2)-(X2+Z2)X-2Y+Z=X²+Y²+Z²=2,求2(X²-Y²-2)-(2X-4Y-3Y²)

解下列方程x2+2y2-3x+y=0;3x2+4y2-x+2y=0x=3,y=-1/2;x=1/3,y=-1/2

若x2+xy-2y2=0,则(x2+3xy+y2)／(x2+y2)=?那假设x或y=o.那XY就不能删掉啦.怎么办?x2+xy-2y2=0(x-y)(x+2y)=0x-y=0,x+2y=0x=y或x=-2yx=y,则原式=(y2+3y2+y

已知x(x-1)-(x2-y)=-3求x2+y2/2-xyx2是x的平方y2是y的平方x2+y2/2是二分之x2+y2x²-x-x²+y=3-x+y=3x-y=-3(x²+y²)/2-xy=(x&su

已知非零实数x,y满足:x2+xy-2y2=0,求(x2+3y+y2)/(x2+y2)的值由x2+xy-2y2=0,x2-y2+xy-y2=0,(x+y)(x-y)+(x-y)y=0,(x-y)(x+2y)=0.得x-y=0或者x+2y=0