We have functions f and g defined as:
f(x) = 5x - 2
g(x) = 4x - 2
We can subtract both functions:
f(x) - g(x) = (5x - 2) - (4x - 2) = 5x - 2 - 4x + 2
Then:
f(x) - g(x) = x
But, by definition, we know that:
(f - g)(x) = f(x) - g(x)
Putting these together:
(f - g)(x) = x
Now, if x = -3:
(f - g)(-3) = -3