2X=3Y,4x-5y=2 -6x+5y=3,3x=4y 2x+3y=5,3x=y-9 3x=1-y,3x=2y-5
来源:学生作业帮 编辑:大师作文网作业帮 分类:数学作业 时间:2024/09/28 17:25:49
2X=3Y,4x-5y=2 -6x+5y=3,3x=4y 2x+3y=5,3x=y-9 3x=1-y,3x=2y-5
2X=3Y (1)
4x-5y=2 (2)
(1)*2-(2)得
5y=6y-2
y=2
将也代入(1)
2x=3*2
x=3
-6x+5y=3 (1)
3x=4y (2)
由(2)得
x=4/3y (3)
将(3)代入(1)得
-6*(4/3y)+5y=3
y=-1
将y=-1代入(3)得
x=4/3*(-1)
x=-4/3
2x+3y=5 (1)
3x=y-9 (2)
由(2)得
y=3x+9 (3)
将(3)代入(1)得
2x+3(3x+9)=5
11x=-22
x=-2
将x=-2代入(3)得
y=3*(-2)+9
y=3
3x=1-y (1)
3x=2y-5 (2)
由(1)得
y=1-3x (3)
将(3)代入(2)得
3x=2(1-3x)-5
3x=2-6x-5
9x=-3
x=-1/3
将x=-1/3代入(3)得
y=1-3(-1/3)
y=2
4x-5y=2 (2)
(1)*2-(2)得
5y=6y-2
y=2
将也代入(1)
2x=3*2
x=3
-6x+5y=3 (1)
3x=4y (2)
由(2)得
x=4/3y (3)
将(3)代入(1)得
-6*(4/3y)+5y=3
y=-1
将y=-1代入(3)得
x=4/3*(-1)
x=-4/3
2x+3y=5 (1)
3x=y-9 (2)
由(2)得
y=3x+9 (3)
将(3)代入(1)得
2x+3(3x+9)=5
11x=-22
x=-2
将x=-2代入(3)得
y=3*(-2)+9
y=3
3x=1-y (1)
3x=2y-5 (2)
由(1)得
y=1-3x (3)
将(3)代入(2)得
3x=2(1-3x)-5
3x=2-6x-5
9x=-3
x=-1/3
将x=-1/3代入(3)得
y=1-3(-1/3)
y=2
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
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