20%X+30%Y+277=2000
20%X+30%Y+277=2000
x+y=20-6 3x+y=30
|x|+|y|=30 2|x|-3|y|=20 求x,y
|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
x-80=y,(1-25%)x+30=(1+20%)y问x=?y=?
已知x+y=30,x-y=20,求2(x-2y)的二次方-132的值?
已知x+y=30,x-y=20,求1/5(x-3y)²-12.7的值
已知x+y=30,x-y=20,求2(x-2y)的平方-132的值
X/30+Y/20=1