解方程 3(2X-Y)+4(X-2Y)=87 2(3X-Y)-3(X-Y)=82 1-0.3(Y-2)=(X+1)/5

来源：学生作业帮编辑：搜搜考试网作业帮分类：数学作业时间：2024/05/04 20:22:22

解方程 3(2X-Y)+4(X-2Y)=87 2(3X-Y)-3(X-Y)=82 1-0.3(Y-2)=(X+1)/5 (Y-3)/4=(4X+9)/20-15 X+Y=
3(2X-Y)+4(X-2Y)=87
2(3X-Y)-3(X-Y)=82
1-0.3(Y-2)=(X+1)/5
(Y-3)/4=(4X+9)/20-15
X+Y= 2800
0.96X+0.64Y=2800*0.92

(1)原式：3(2X-Y)+4(X-2Y)=87
2(3X-Y)-3(X-Y)=82
=> 10x-11y=87
3x+y=82 (=> y=82-3x代入10x-11y=87)
=> 解为：x=23,y=13
(2)原式：1-0.3(Y-2)=(X+1)/5
(Y-3)/4=(4X+9)/20-15
=> 2x+3y=14
4x-5y=-276
=> 4x+6y=28
4x-5y=-276
=> 解为：x=-379/11,y=304/11
(3)原式：X+Y= 2800
0.96X+0.64Y=2800*0.92
=》 X+Y= 2800
3x+2y=8050
=> 2X+2Y= 5600
3x+2y=8050
=>解为：x=2450,y=350
完成

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 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-( 解方程x+y+(x+y/2)=15 3x+5y+4(x+y/2)=62 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 解方程 3(2X-Y)+4(X-2Y)=87 2(3X-Y)-3(X-Y)=82 1-0.3(Y-2)=(X+1)/5 2(x+y) 3x+3y=24 x+y/2x x y/2y= 1 解方程：3x+2y/4=2x+y/5=x-y+1/6要详细过程已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y