Hoping I can get some help on a word problem.

If the price for a product is given by p=900-x^2, where x is the number of unites sold, then the revenue is given by R=px=900x-x^3. How many units must be sold to give zero revenue?

I plugged p=900x-x^3 into the calculator and got the zeros like my teacher said but I'm not sure what to do after.

Question

Hoping I can get some help on a word problem. 

If the price for a product is given by p=900-x^2, where x is the number of unites sold, then the revenue is given by R=px=900x-x^3. How many units must be sold to give zero revenue?

I plugged p=900x-x^3 into the calculator and got the zeros like my teacher said but I'm not sure what to do after.

anonymous · Answer

900-x^2=900x-x^3
or x^3-x^2-900x+900=0
make factors and find the value of x