3(x+y)+2(x-y)=20 0.3x+0.6y=60 x=?y=?
来源:学生作业帮助网 编辑:作业帮 时间:2024/10/23 17:43:55
3(x+y)+2(x-y)=20 0.3x+0.6y=60 x=?y=?
3(x+y)+2(x-y)=20 0.3x+0.6y=60 x=?y=?
3(x+y)+2(x-y)=20 0.3x+0.6y=60 x=?y=?
3(X+Y)+2(X-Y)=20可以化简为5X+Y=20.1式
0.3X+0.6Y=60可以化简为X+2Y=200.2式
联立1式和2式消元即可以求解这组二元一次方程组
X=-160/9 Y=980/9
有题设有:
5x+y=20 (1) x+2y=200 (2)
(1)的2倍减去(2)有:9x=-160,x=-160/9
(2)的5倍减去(1)有:9y=980,y=980/9
x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20
{(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20
4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6
3(x+y)+2(x-y)=20 0.3x+0.6y=60 x=?y=?
x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2
(x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)=
(x+y)(x-y)+(x-y)平方-(x-y)(3x-y) 其中x=-2 y=3分之一
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
(x+y)(2x-3y)=?
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
已知x-y=3,求[(x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值
已知3x =2y 求x/x+y+y/x-y-y²/x²-y²
若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值
2x+3y=9 x+y=20
x+y=20 3x-2y=5x+y=203x-2y=5
2元一次方程组 2/x+y+3/x-y=6 4(x+y)-3(x-y)=-20
解方程组;x+y/2=x-y/3=6 4(x+y)-3(x-y)=-20
1/(x+y)-1/(x-y)=-3/20,2/(x+y)+3/(y-x)=-(1/5)急啊!