当2y-x=5时,5(x-2y)2-3(-x+2y)-60=______.
当2y-x=5时,5(x-2y)2-3(-x+2y)-60=______.
当x=1,y=-2时,代数式x-(x+y)+(x+2y)-(x+3y)+…-(x+99y)=______.
已知方程2x+3y=2,当x与y互为相反数时,x-y=______.
已知2x+3y=5,则6x-4y-2(x-5y)=______.
若|3x-y-7|+(5x+2y-8)2=0,则x-y=______.
1、当(x+y)/(x-2y)=3时,2x/y=?
当x=5 y=3时,求(x-y)2-(x+y)的值
1.在方程2x+y=5中,用含x的代数式表示y,得y=____,当x=3时y=______.
当点(x,y)在直线x+3y-2=0上移动时,则3x+27y+1的最小值为______.
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
(1)在同一坐标系中,画出函数y=x,y=-x,y=3x,y=-3x的图像(2)已知y-5与x成正比例,当x=-1时y=
先化简再求值X-{Y-2X+〔3X-2(2X+Y)+5Y〕},并求当X-Y=2的值