若x加y=-5,xy=3,求根号y分之x
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(3x-5xy+3y)/(x+xy+y)分式上下同除xy,得,(3/y-5+3/x)/(1/y+1+1/x)=1/3再问:太给力了,你的回答完美解决了我的问题!
学了一元二次方程了吗?
1/x-1/y=(y-x)/xy=3所以y-x=3xyx-y=-3xy所以原式=[5(x-y)+3xy]/[3(x-y)-xy]=[5(-3xy)+3xy]/[3(-3xy)-xy]=-12xy/(-
1/x+1/y=2y+x=2xy(2x-xy+2y)=2(x+y)-xy=3xy(3x+5xy+3y)=3(x+y)+5xy=11xy(2x-xy+2y)÷(3x+5xy+3y)=3xy/11xy=3
xy/(x+y)=2∴xy=2(x+y)(3xy-x-y)/(3x-5xy+3y)=[6(x+y)-x-y]/[3x+3y-10(x+y)]=5(x+y)/[-7(x+y)]=-5/7
(1)+(2)得x²+2xy+y²+5x+5y=0(x+y)²+5(x+y)=0(x+y)(x+y+5)=0∴x+y=0或x+y=-5
0或-5过程看图再问:你QQ好能给我吗?以后不会的可以问你。再答:本人资料里可以找到
1/x+1/y=5两边乘以xy得y+x=5xy∴x+y=5xy3x+4xy+3y/x+3xy+y=[3(x+y)+4xy]/[(x+y)+3xy]=(15xy+4xy)/(5xy+3xy)=19xy/
x/y+y/x=(x²+y²)/xy=[(x+y)²-2xy]/xy=(x+y)²/xy-2=25/3-2=19/3
哎,初中没好好学,方程式y=x^2-5x+6要有实数解,必须b^2-4ac>=0,即(-5)^2-4(6-y)>=0,得出y>=-0.25估计你这y值肯定是大于0的,所以必然有两个不
∵x-y=-3∴(x-y)²=(-3)²∴x²-2xy+y²=9∴二分之x的平方加y的平方减xy=9/2
=(x^4+x^3y)+(y^4+xy^3)+(4x^3y+4x^2y^2)+(4xy^3+4x^2y^2)+x^2y+xy^2=x^3(x+y)+y^3(x+y)+4x^2y(y+x)+4xy^2(
xy/(x+y)=2(x+y)/xy=1/21/x+1/y=1/2(3x-xy+3y)/(-x+3xy-y)=(3/y-1+3/x)/(-1/y+3-1/x)=[3(1/x+1/y)-1]/[(3-(
X+y=3xy=-5X-y=?(x-y)^2=(X+y)^2-4xy=9+20=29则x-y=±根号29
3(x^2-xy)-xy+y^2=3(x^2-xy)-(xy-y^2)=3*5-(-3)=15+3=18
根号(Y/X)+根号(X/Y)=根号(XY)/X+根号(XY)/Y=根号(xy)*(1/x+1/y)=根号3*(x+y)/xy=根号3*(-6)/3=-2根号3
得y-x=3xyx-y=-3xy原式=-15xy+2xy/-3xy-4xy=-13/-7=13/7
x²+xy+5y=3……………………①y²+xy+5x=﹣3.………………②①+②得:x²+2xy+y²+5x+5y=0﹙x+y﹚²+5﹙x+y﹚=0
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