x+y=180 x/12+y/8=20
(x*x+y*y)(x*x+y*y)-(x*x+y*y)=12 求x*x+y*y等于多少
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
解方程组﹛x+y=180,x/12+y/8=20
解方程 {x+y=20 x-y=12
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
Y-X=45 (85%Y-X)×8=(Y-35-X)×12
Y-X=45 (80%Y-X)×8=(Y-35-X)×12
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
这个方程怎么解2x=8y 20x+12y=2300x=?y=?