3y-3分之1y等于多少
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/03 11:15:23
原式=2/3-2(x+y)=2/3-2×(-3)=2/3+6=20/3
1/x-1/y=2y-x=2xyx-y=-2xy(3x+7xy-3y)/(2x-3xy-2y)=[3(x-y)+7xy]/[2(x-y)-3xy]=[-6xy+7xy]/[-4xy-3xy]=xy/[
1/X-1/Y=5(Y-X)/XY=5Y-X=5XY(3x+7xy-3y)/(2x-3xy-2y)=[3(X-Y)+7XY]/[2(X-Y)-3XY]=[-3(Y-X)+7XY]/[-2(Y-X)-3
x分之1减y分之1等于2(y-x)xy=2y-x=2xyy减xy减x分之3x加xy减3y=[3(x-y)+xy]/(y-x-xy)=(-6xy+xy)/(2xy-xy)=-5xy/xy=-5
(y-2)/(y-3)=1/(2-3y)(y-2)/(y-3)-1/(2-3y)=0(y-2)(2-3y)-(y-3)=0-3y²+8y-4-y+3=03y²-7y+1=0Δ=49
3x/4+2y=(2x+y)/5=(x-y+1)/6则3x/4+2y=(2x+y)/5―→15x+40y=8x+4y→7x+36y=0――①(2x+y)/5=(x-y+1)/6―→12x+6y再问:麻
x+2y=(y-x)/4x+2y=(2y-1)/3化简此二元一次方程组5x+7y=0→15x+21y=0……………………①3x+4y=-1→15x+20y=-5…………………②解此二元一次方程组①-②
1/x-1/y=3y-x=3xyx-y=-3xy(5x-xy-5y)/(x-xy-y)=(-15xy-xy)/(-3xy-xy)=4
在1/x+1/y=3的两边分别乘以xy,则y+x=3xy.将此代入所求的式子,有(3*3xy+xy)/(3xy-xy)=5比反了,抱歉啊!
x分之1减y分之1等于31/x-1/y=3(y-x)/xy=3y-x=3xy所以x-xy-y分之5x-xy-5y=(-3xy-xy)分之(-15xy-xy)=-4分之(-16)=4
简单!列个方程:(2X-Y)/(X+Y)=2/3会解这个分式方程吧最后结果是1.25(也就是5/4)
x/4=y/4=z/5x=yz=5/4x(x+y)/(x-2y+3z)=(x+x)/(x-2x+3*5/4x)=2x/(11/4x)=8/11
由原题知:4x=3y,所以x=3y/4.把它代入4x-5y/4x+5y,最后化简得原式等于-1/4,应该选C
x*3/4=y*2/7x:y=2/7:3/4根据比例的基本性质:外项的积等于内项的积.把乘积的形式改写成比的形式就可以了.如有帮助,请采纳.谢谢!
3X=4Y两边除以3YX/Y=4/3(X-Y)/X=X/X-X/Y=1-4/3=-1/3
3分之2x+y等于5分之x+3y同乘以15,得10x+5y=3x+9y7x=4yx=4y/75分之x+3y等于1x+3y=54y/7+3y=5同乘以7,得4y+21y=35y=7/5所以x=4y/7=
是.(x-y)/(x+y)=1/22(x-y)=x+y2x-2y=x+yx=3yx/y=3
1/x+1/y=-1/(x+y)两边同时乘x+y得1+y/x+1+x/y=-1所以y/x+x/y=-3