Please help

This is going to be a circe, just did a similar one for you.

Once you have the centre of the circle the minimim x value will be the centre x value minus the radius.

x^2 -14x + y^2 - 48y = 0

x^2 - 14x + 49  + y^2  - 48y + 576   =  49 + 576

(x - 7)^2 + ( y - 24)^2 =  625

x is minimized/maximized when y = 24

(x - 7)^2 =  625        take both roots

x - 7  =  25          or        x  - 7 =  -25

x = 32                 or        x =  - 18 

So....x = -18  is the minimum value for x