Question 997545
f(x)=9x^3+2x^2-5x+4 and g(x)=5x^3-7x+4. What is f(x)-g(x)? 
I've been on this question for a while now and I'm really struggling. Help?
<pre>{{{f(x) = 9x^3 + 2x^2 - 5x + 4}}} and {{{g(x) = 5x^3 - 7x + 4}}}
f(x) =    9x<sup>3</sup> + 2x<sup>2</sup> - 5x + 4 --------->    9x<sup>3</sup> + 2x<sup>2</sup> - 5x + 4
g(x) = - (<u>5x<sup>3</sup>       - 7x + 4</u>) -------->  - <u>5x<sup>3</sup>       + 7x - 4</u>          
                                           <b>4x<sup>3</sup> + 2x<sup>2</sup> + 2x -------></b> {{{highlight_green(Final_answer)}}}