Question

If f(x) = 3^2 + 10x and g(x) = 2x-4, find (f-g)(x).

Answer 1

What we know:      

$f(x)=3^2+10x\\g(x)=2x-4$                

(Also, $3^2=9$)

What we need to solve:

$(f-g)(x)$             (This is equal to $f(x)-g(x)$)

How you have to subtract $f(x)$ with $g(x)$ to get:

$(f-g)(x) = f(x)-g(x) = 9+10x+2x-4 = 12x+5$

Thus, the answer would be:

$12x+5$