Question 69719
12/(9+x)+12/(9-x)=3
[12(9-x)+12(9+x)]/(9+x)(9-x)=3
(108-12x+108+12x)/(81-x^2)=3
216/(81-x^2)=3
3(81-x^2)=216
243-3x^2-216=0
-3x^2+27=0
x^2=-27/-3
x^2=9
x=3 which is the current
proof
12/(9-3)+12(9+3)=3
12/6+12/12=3
2+1=3
3=3