It has been a great many years since I did any algebra, now my son hits me with this:-
x squared + 2x = y find x and y
x squared + 2x = 48 find x
The factors of 48 that differ by 2 are 6 and 8, so x=6
or -6 and -8 so x=-8 as that is 2 less than -6.
We are looking for the factors of -48 that add to give 2,
these are -6 and 8, since
Two values multiplied give zero means x-6=0 or x+8=0,
so x=6 or -8.
For the first one, you need more information, because you can take any x,
square it and add 2x and call the answer y.