已知x=-5,y=5分之1,求x的平方乘以x的2m次方 y的n 1次方的平方的值-搜答案-智慧作业帮

解1/x+1/y=5即(y+x)/xy=5∴y+x=5xy∴(2x+3xy+2y)/(x-2xy+y)=[2(x+y)+3xy]/[(x+y)-2xy]=[2×5xy+3xy]/(5xy-2xy)=(

1/x-1/y=3x-y=-3xy(2x+3xy-2y)/(x-2xy-y)=[2(x-y)+3xy]/[(x-y)-2xy]=(-3xy)/(-5xy)=3/5

1/x+1/y=(x+y)/(xy)=5x+y=5xy(2x-3xy+2y)/(x+2xy+y)=(2*5xy-3xy)/(5xy+2xy)=(10-3)/(5+2)=1

∵（2x+y)/2=(5x+2y)/4=1∴{2x+y=2(1){5x+2y=4(2)(1)==>y=2-2x代入（2）5x+2(2-2x)=4x+4=4,∴x=0,y=2∴(x+2y+1)/(2x-

(x分之1)+(y分之1)=5（x+y)/xy=5x+y=5xy代入（x+2xy+y)分之(2x-3xy+2y)=7xy分之7xy=1

由4x+y-4x-6y+10=0得(4x-4x+1)+(y-6y+9)=0(2x-1)+(y-3)=0(2x-1)=0(y-3)=0x=1/2y=3代入所求算式即可求出结果（不好意思,看不清你的所求算

2分之3x+y=14分之5x-y=1,3x+y=2(1)5x-y=14(2)由(1)+(2)式得8x=16x=2y=-42x-3y+7=2*2-3*(-7)+7=32

x=5y=-2-1/6

∵x/4=y/5　∴x:y=4:5　∵y/5=z/3　∴y:z=5:3　∴x:y:z=4:5:3

x+y=2又20分之19x-y=5分之1等式左边加左边,右边加右边.x+y+x-y=20分之632x=20分之63x=40分之63y=40分之55

1/X-1/Y=5Y-X=5XY,(X-3XY-Y)/(3X+5XY-3Y)=［-(Y-X)-3XY］/［-3(Y-X)+5XY］=(-8XY)/(-10XY)=4/5.

已知：1/X-1/Y=5通分：(Y-X)/XY=5,倒数：XY/(Y-X)=1/5.

1/x-1/y=3(y-x)/xy=3y-x=3xyx-y=-3xy(5x+xy-5y)/(x-xy-y)=[5(x-y)+xy]/[(x-y)-xy]=[5*(-3xy)+xy]/[(-3xy)-x

1/x－1/y＝5,通分得：(y-x)/(xy)＝5,即y－x＝5xy,或写作x－y＝-5xy,代入所求式,得：(3x+5xy-3y)/(x-3xy-y)＝[3(x-y)+5xy]/[(x-y)-3x

1/x-1/y=3(y-x)/xy=3y-x=3xyx-y=-3xy所以原式=[5(x-y)+3xy]/[(x-y)-2xy]=(-15xy+3xy)/(-3xy-2xy)=(-12xy)/(-5xy

∵x分之1-y分之1=3∴y-x=3xy∴x-xy-y分之5x+xy-5y=-4xy分之-4xy=1

因为x＋y/2=3x＋4y/5=1,所以x＋y=2,3x＋4y=5所以解方程组得x=3,带入x＋5y＋6/3x－y＋1,得4/11

原式等价于10(x+1)=5(y+3)=4(x+y)10(x+1)=5(y+3)可得2x-y=15(y+3)=4(x+y)可得4x-y=15解得x=7y=13x+2y+3=363x+2y+1=48两式

5x=4y另x=4t,y=5t所以x/y=4t/5t=4/5(x+y)/y=(4t+5t)/5t=9/5再问：为什么5X=4Y再答：因为5x-4y=0移项5x=4y再问：为什么要设4T和5T再答：为了