Question 989269
(1) y=x+8
(2) 1/x+1/y=1/3

Sub (1) into (2)


(1/x)+(1/(x+8))=1/3

(x+8)/(x(x+8))+(x)/(x(x+8))=1/3

(x+8)/(x^2+8x)+(x)/(x^2+8x)=1/3

2x+8/(x^2+8x)=1/3

2x+8=1/3(x^2+8x)

1/3x^2+8/3x-2x-8=0

1/3x^2+2/3x-8=0

x^2+2x-24=0
.
.
.
[x=4, x=-6]

If x=4:

y=x+8

[y=12]

If x=-6

y=x+8

y=[2]

-Aμstin