若x y=2,xy=负3,3x的平方y加3xy的平方的值是-搜答案-灵鹊做题网

x=-1/5y=-1/35x²y-2xy²-3xy-2xy-5x²y+2xy²=-5xy=-5(-1/5)(-1/3)=-1/3

1.2(Xy+Xy)-3(Xy-xy)-4Xy=2*2xy-0-4xy=4xy-4xy=02.1/2ab-5aC-(3acb)+(3aC-4aC)=1/2ab-5ac-3acb-ac=1/2ab-6a

-xy（x^2y^5-xy^3-y)=-(xy^2)^3+(xy^2)^2+xy^2=-(-2)^3+4-2=8+4-2=10

(-3x^y+2xy)-(4x^+xy)=-3x^y+2xy-4x^-xy=-3x^y+xy-4x^所以填上-3x^y+xy-4x^

x+y=5xy=-3(2x-3y-2xy)-(x-4y+xy)=2x-3y-2xy-x+4y-xy=x+y-3xy=5-3×(-3)=5+9=14

x+（xy-4x）-3y=x-4x-3y+xy=-3(x+y)+xy=1-3=-2

3xy-[2xy-2(xy-2分之3xy)+xy]+3xy=6xy-[2xy-2xy+3xy+xy)=6xy-4xy=2xy=2×3×3分之1=2

=3x平方y-2x平方y+6xy-3x平方y+xy=-2x平方y+7xy=-2*1*(-2)+7*(-1)*(-2)=4+14=18

因为〔〕-〔X^2+3XY〕=-XY-1/3Y^2,求被减数为多少,被减数=X^2+3XY+（-XY-1/3Y^2）=X^2+3XY-XY-1/3Y^2=X^2+2XY-1/3Y^2

（2x-3y-2xy）-（x-4y+xy）=2x-3y-2xy-x+4y-xy=（2-1)x+(-3+4)y+(-2-1)xy=x+y-3xy因为x+y=5,xy=-3所以原式=5+9=14

x²＋xy＝3………………………①y²＋xy＝－2……………………②①＋②得：x²＋2xy＋y²＝1（x＋y）²＝1x＋y＝±1∴x²＋3x

(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)=-2xy+2x+3y-3xy-2y+2x-x-4y-xy=-6xy+3x-3y=-6xy+3*(x-y)当时,原式=-6*1+3*

由A=5x*2y-3xy*2+4xy,B=7xy*2-2xy+x*2y得,A+B=6x*2y+4xy*2+2xy则,所求的式子可转化为-0.5x(6x*2y+4xy*2+2xy)-5x*2y-3xy*

(3x^2+2xy)/xy-(2x^2-xy)/xy=(3x^2+2xy-2x^2+xy)/xy=(x^2+3xy)/xy=x(x+3y)/xy=(x+3y)/y

x+y=3xyx^4+y^4+2(xy)^2=9(xy)^2x^4+y^4=7x^2y^2xy的负二次方+x的负二次方y=x^2/y^2+y^2/x^2=x^4+y^4/x^2y^2=7

3/5再问：详细过程呢再答：y-x=3xyx-y=-3xy代入得：(-6xy+3xy)/(-3xy-2xy)=-3/-5=3/5

1.xy不等于0,所以x^2-y^=xy两边各除xy得x/y-y/x=1所以2+xy负一次方-x负一次方y=32.已知X的m-2次方幂*X的3m次方幂=X的6次方幂所以m-2+3m=6,得m=21/2

=xy(1-2y^2)=-0.119616

（-2xy²／3x³y）的负3次方=（-2y²/3x²）的负3次方=（-3x²/2y²）³=-27x的6次方/8y的6次方

x+y=5xy（2x-3xy+2y)/(x+2xy+y）=[2（x+y）-3xy]/[(x+y)+2xy]=(2×5xy-3xy)/(5xy+2xy)=7xy/7xy=1再问：若x＋1/x＝3,求(x