How do I factorize the following:
3x+33
x-33
-3x+33
30x cubed-5x squared

Diana had chocolate, and ate some, leaving 0.75 of it for Sarah. 

Sarah ate 18.5 grams of it and return the rest to Diana, which was 65% of the original chococate. 

how much chocolate did Diana have at the beginning?

and the solution is: 

0.75x-18.50=0.65x 

0.75x-0.65x=18.50
0.1x=18.50
x=185

so Diana had 185 grams of chocolate. 

Hope this helped