Given that $f(x)=x^{2}+3 x-70$ and $g(x)=x-7$, find $f(x)-g(x)$ and express the result as a polynomial in simplest form.

Step 1 ：Subtract g(x) from f(x) term by term: \(f(x) - g(x) = (x^2 + 3x - 70) - (x - 7)\)

Step 2 ：Simplify the expression: \(x^2 + 3x - 70 - x + 7 = x^2 + 2x - 63\)

Step 3 ：\boxed{x^2 + 2x - 63}