[2000+20(x-y)]/x+y = (2000-20y)/y 怎么化简
|x-y |=x-y |x |=1999 |y |2000,求x+y的值
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
化简求值:(x+y)-(2x+1/2y)-(3x+1/6y)-(4x+1/12y)-(5x+1/20y)-.(10x+1
4(x+y)^2+25-20(x+y)怎么解,
化简求值:[(x+y)(x-y)-(x-y)²+2y(x-y)]÷4y,其中x=二分之一,y=2
4(x+y)-20(x+y)+25
{(x,y) |x|+|y|
x>y?x:y
有这样一道题,计算:(x-y)[(x+y)(x+y)-xy]-(x-y)[(x-y)(x-y)+xy]的值,其中x=20
20%X+30%Y+277=2000