Okay so this is a very hard conceptual question. We need to prove that (x, y) is the ordered pair when "f(x) = g(x)".
"f(x) = g(x)" represents the point where the lines share a point or basically the intersection point of the two functions.
To prove that the intersection point is (x, y) let's find the x and y values at the point of intersection.
f(x) ----> the x-value is x and the y-value is f(x)
g(x) -----> the x-value is x and the y-value is g(x)
We know that f(x) = g(x) so we know that the y values match too.
We can also substitute a variable y for f(x) or g(x) (It is simply the y-value when x is plugged in for x. I know it sounds a bit confusing.).
So the solution when f(x) = g(x) is (x, y)!!!