若2x y=3求4x乘2y-搜答案-百度作业网

括号应该成对,还有一个括号在哪里?能不能把你的叙述用数学的语言表达出来?

xy/(2x+y)-xy/(2x-y)=3xy/(2x-y)+xy/(2x+y)=4；一、两公式对加得2xy/(2x+y)=7xy=(2x+y)*7/2二、把xy代入原公式求解就行了：(2x+y)*7

x^+2xy+y^+4=16(x+y)²=16-4=12(1)x^-2xy+y^=16(x-y)²=16(2)(1)-(2)2y*2x=-4xy=-1(3xy+6y^)+|x^-(

因为x-y=4xy所以x-2xy-y=2xy2x+3xy-2y=11xyx-2xy-y分之2x+3xy-2y=5.5

2x+y=0可得： y=-2x于是(x-2y)/(x²+xy)*(x²-y²)÷(x²-4xy+4y²)/x=(x-2y）/x(x+)*（x

(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)=-6xy+3x-3y=-6×(-2)+3×1=15

原式=3x-3y-6xy=3-12=-9

x=3y再答：带入再答：3.5

（4xy+12y)+[7x-(3xy+4y-x)]=4xy+12y+7x-3xy-4y+x=xy+8x+8y=xy+8(x+y)=(-2)+8*3=-2+24=22

(-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*

因为x²+2y-根号2乘y=17+4根号2,所以x²+2y=17,-y=4解得y=-4,x²=25所以x=±5所以x-y=5-(-4)=9,或x-y=-5-(-4)=-5

2x的立方乘y+4x的平方乘y的平方+2xy的立方=2xy(x²+2xy+y²)=2xy(x+y)²=2×2×4²=64

1.若x分之1-y分之1=2,则求x-xy-y分之3x+xy-3y=0的值.若x分之1-y分之1=2变形（y-x）/xy=2,(y-x)=2xy(3x+xy-3y)/(x-xy-y)=[3(x-y)+

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

x²+y²-4x-6y=-13x²+y²-4x-6y+13=0x²-4x+y²-6y+13=0（x²-4x+4）+（y²

xy^2*(-x^2y^2)(1/2xy^3)^2=-xy^2*x^2y^2*1/4x^2y^6=-1/4x^5y^10(xy^2)^5=x^5y^10当xy^2=2时,原式=-1/4*2^5=-1/

得y-x=3xyx-y=-3xy原式=-15xy+2xy/-3xy-4xy=-13/-7=13/7

（Y－X）÷（XY）＝3可变形为Y-X=3XY（2X＋3XY－2Y）÷（X－2XY－Y）=(2X-2Y+3XY）÷(X-Y-2XY)={2（x-y)+3xy}÷(X-Y-2XY)={2(3xy)+3x

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

(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)=-2xy+2x+3y-3xy-2y+2x-x-4y-xy=-6xy+3x-3y=-6*(-2)+3*1=15不懂可追问,有帮助请采