# Math Help - Product Rule - Marginal Revenue (Fill in the Blanks)

1. ## Product Rule - Marginal Revenue (Fill in the Blanks)

Hi there everybody,

I wonder if anyone could help me solving the following problem:

I would really appreciate if you could give step by step solutions too. Thank you very much, everyone.

2. Originally Posted by wdma

let $x$ be the number of additional people

$R(x) = (30+x)(120-2x)$

take the derivative to find $R'(x)$

3. Hey Skeeter, actually I wanted some help taking the derivative to find R'(x).
I got the first part (wanted to confirm), but it's in taking the derivative that I've been stuck with.

Thank you very much for your help

4. Originally Posted by wdma
Hey Skeeter, actually I wanted some help taking the derivative to find R'(x).
I got the first part (wanted to confirm), but it's in taking the derivative that I've been stuck with.

Thank you very much for your help
there are two ways to go ...

1. use the product rule

or

2. expand the product and use the power rule