求化简 y=(x-5)(100-7(x-7))急
化简,亲快啊啊急!(3x-2y)(7x-y)-(4x+3y)(x-y)
7x+[-3x-3(x-2y)]-[5x-(2x-y)]
1.已知x:y:z=4:5:7,求:(一)2x+3y+z/5z; (二)x+y/y+z 非常急,
已知5x=7y,x与y( )
(x-y)7÷(y-x)4+(-x-y)8÷(x+y)5.
求化简 y=(x-5)(100-7(x-7))帮帮忙啦
求化简 y=(x-5)(100-7(x-7))
(x-4y)分之(3x)+(4y-x)分之(x+y)-(x-4y)分之(7y)
已知(2y-x)/(7x-5y),则x/y的值为( )
二元一次方程,5分之2X+Y=1 X+7分之2Y=3(要过程)急.
去括号并合并同类项(1)3x-2(x+7)+2(2x+5) (2)(4x-3y)-[-(3y-x)+(x-y)]-5x
化简求值(x+5y)(x+4y)-(x-y)(x+y),其中x=一又2/5,y=-1/7