(3分之1xy)²×(-12x²y²)除以(-3分之4x³y)-搜答案-拍题作业网

原式=-3xy^2*144y^2/x^2*x^3/216y^6=-2*1/y^2=-2/y^2

2分之3X^(3)Y-6X^(2)Y^(2）+9XY^(3)

(3x的平方+2xy-2分之1x)-(2x的平方-xy+x)=3x+2xy-x/2-2x+xy-x=x+3xy-3x/2

（3x²+2xy-1/2x）-（2x²-xy+x）=3x²+2xy-1/2x-2x²+xy-x=x²+3xy-3/2x

=(2X/3Y)*(3X/4Y)*(4/xy)=(2x*3x*4)/(3y*4y*xy)=2x/(y^3)

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

-8xy√2x

您好：（1）-2分之1xy（3y²-2xy+3x²y）=-3/2xy³+x²y²-3/2x³y³（2）已知x=4,y=8分之1,求

原式=-x²y³+3x²y³=2x²y³

/>∵12/x﹥0且3/xy﹥0,18/xy³﹥0∴x﹥0,y﹥0原式=√(12/x)×√(3/xy)÷√(18/xy³)=√(12/x×3/xy÷18/xy³)=√(1

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

原式(-xy/3)²*[xy(2x-y)-2x(xy-y²)]=(x²y²/9)(2x²y-xy²-2x²y+2xy²)

原式=3x²y-(2xy-2xy+3x²y+xy)=3x²y-(3x²y+xy)=3x²y-3x²y-xy=-xy=-3×(-1/3)=1

设1/x-1/y=t(5x+xy-5y)/(x-xy-y)=(1-5(1/x-1/y))/(-1-(1/x-1/y))=(5t-1)/(t+1)至于是1/x-1/y=3还是1/y-1/x=3都差不多

(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

(2分之1x平方y—2xy+y平方）*3xy=1/2x²y*3xy-2xy*3xy+y²*3xy=3/2x³y²-6x²y²+3xy&sup

x-y分之xy=-3分之1xy分之(x-y)=-3x-y=-3xyx-2xy-y分之2x+3xy-2y=(-6xy+3xy)/(-3xy-2xy)=3/5

x-x^2分之x^2-1×1-y分之xy-x=(x+1)(x-1)/x(1-x)*[x(y-1)]/(1-y)=(x+1)/(-x)*(-x)=x+1（xy-x^2）÷xy分之x-y=x(y-x)*x

(3x²+2xy-x/2)-(2x²-xy+x)=x²+3xy-3x/2

原式=5x根号(xy)/3根号(y/x)*1/3根号(x/y)=5/9*根号(xy*x/y*x/y)=5x/9y根号(xy)