Alex had (3x + 1) yards of silk. he then purchases (x2 + 5x + 4) packages each containing (2x + 1) yards of silk. if he uses (2x3 + 8x2 + 10x + 4) yards of silk to make a kite, how much silk remains?

Alex has originally  yards of silk.

Then he purchases  packages, each containing  yards of silk, so he purchases a total of 

                  yards of silk.

Distributing  over , and 1 we have



.

The original amount of silk, and the purchased amount are a total of

.           
 

Of these,  are used. Thus, in the end the amount left is 
                 :



  yards

He gained 60,900 dollars for that land