The product of two positive numbers...

The product of two positive numbers is 53. Express their sum as a function of one of the numbers.

 

I wrote 2 ways:

f(x)=

S=x^2+y^2

x+y=53

y=53-x

x^2+(53-x)^2= S

x^2+2,809-106x+x^2

2x^2-106x+2,809

-b/2a=106/4=26.5

x=26.5

Or

x.y=53

Therefore, y=53/x

x+y=x+53/x

=x^2+53

 

Please tell me where I went wrong (If there's anything I did well in the first place lol) and thank you