Question

7/3=(36-y)/x+y/(x+6)

Answer 1

两个方程相加

7/3+8/3=(36-y+y)/x+(y+36-y)/(x+6)

5=36/x+36/(x+6)

两边乘x(x+6)

5x^2+30x=36x+216+36x

5x^2-42x-216=0

(x-12)(5x+18)=0

x=12,x=-18/5

分别代入

x=12

7/3=(36-y)/12+y/18=(108-3y+2y)/36

108-y=84

y=24

x=-18/5

7/3=-5(36-y)/18+5y/12=(-360+10y+15y)/36

25y-360=84

y=444/25

所以x=12,y=24

x=-18/5,y=444/25