2x(m 3x)=6x^2y^2 n,求m,n

设x-y=mx+y=n则6m-2n=143m+n=5解得m=2n=-1即x-y=2x+y=-1解得x=1/2y=-3/2

由(1)得3x+3y+2x-2y=365x+y=36(3)由(2)得4x+4y-3x+3y=-20x+7y=-20(4)(3)×7-(4)得34x=272∴x=8把x=8代入(3)得y=-4∴x=8y

方法一：直接解出x,y的值,代入方程即可解得m2x+y=6m1）3x-2y=2m2）1）*2+2）,得7x=14mx=2my=2m代入(x/3)-(y/5)=4（2/3-2/5）m=4m=15方法2,

3x-5y=2m①3x+5y=m-18②，①+②得：6x=3m-18，即x=3m-186；①-②得：-10y=m+18，即y=-m+1810，根据题意得：x+y=0，即3m-186=m+1810，去分

{(x+y)/2+(x-y)/3=63(x+y)+2(x-y)=36(1)4(x+y)-3(x-y)=-20(2)由（1）*3+(2)*2得9(x+y)+6(x-y)+8(x+y)-6(x-y)=36

这样算,分离变量:x²+x=(x+1)²-(x+1)然后,除下来,就等于x+1-1=x注意,x≠-1!

3x^2(x-y)+6x(y-x)=3x^2(x-y)-6x(x-y)=(x-y)(3x^2-6x)=3x(x-y)(x-2)

(x-y)^2*(y-x)^2*(x-y)^6=(x-y)^2*(x-y)^2*(x-y)^6=(x-y)^10再问：能详细一点吗?我,初一的再答：(x-y)^2=(y-x)^2=(x-y)^2*(x

1)x(x-y)(x+y)-x(x+y)^2=x((x-y)(x+y)-(x+y)^2)=x(x^2-y^2-x^2-2xy-y^2)=x(-2xy-2y^2)=-2xy(x+y)2)（2a+b)(2

X+Y分之X-Y等于3x=-2yX+Y分之2(x-y)减X+Y分之3X+Y=(-x-3y)/(x+y)=1

(x+y)ˆ2-2(x+y)(x-y)+(x-y)ˆ2=（x+y-x+y）^2=(2y)^4=4y^2如果满意请点击右上角评价点【满意】即可~再问：这个我看不懂，能不能写下来啊，谢

第二个方程是不是写错了2/（x+y）+3/（x-y）=6是这样吗

先一个一个的展开括号项,再同项合并就行了啊[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x=[xx-xy-(xy-yy)+x(x-y)+y(x-y)]÷2x=[xx-xy-xy+yy+xx-

2x-3y=11-4m①3x+2y=21-5m②要不你自己算我给你说方法①②连解,x=(21-5m)/13y=(9+2m)/13让后代入x+3y=20-7m,中求出m

解方程组2x−3y＝11−4m3x+2y＝21−5m得x＝85−23m13y＝18+4m26把x，y代入二元一次方程x+3y+7m=20得85−23m13+3(18+4m)26+7m=20解得m=2故

3(x+y)-4(x-y)=4(x+y)/2+(x-y)/6=1令a=x+y,b=x-y3a-4b=4(1)a/2+b/6=1则3a+b=6(2)(2)-(1)5b=2b=2/5a=(6-b)/3=2

若(x-y)/(x+y)=3那么x-y=3(x+y)x-y=3x+3y故x=-2y所以(x+2y)/(6x-7y)=(-2y+2y)/(6*(-2y)-7y)=0如果不懂,请Hi我,祝学习愉快!

原式=(x²-4y²+4x²-8xy+4y²)÷6x=(5x²-8xy)÷6x=(5x-8y)/6

x（x*x-1)+x(5-x*x)-6y+7=-x+5x-6y+7=2(2x-3y)+7=2*(-4)+7=-8+7=-1再问：能在写详一点吗-x+5x-6y+7再答：x（x*x-1)+x(5-x*x

很累-3x-2y