1200+4y=500x 2400+20x=20y
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
4X+2Y=58 X+Y=20 X=?Y=?
已知x+y=4,x²-y²=20,则x-y=?
x平方-y平方=20,x+y=4求x-y=?
已知x-y=4,x²-y²=20,求x-y的值
x^+y^-4x+8y+20=0,则x+y的值为多少?
已知方程组4x+2y=1,20x+8y,求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
4(x+y)-20(x+y)+25
已知x²+y²+4x-8y+20=0 x=?y=?(x²+y²)²+y