a boy is building a pyramid out of building blocks. he put 20 blocks in the first row, then he puts 19 blocks in the row above, and so on. find the total number of blocks he needs. find the total number of blocks he need

Acertain company's main source of income is a mobile app. the company's annual profit (in millions of dollars) as a function of the app's price (in dollars) is modeled by p(x)=-2(x-3)(x-11)p(x)=? 2(x? 3)(x? 11) which app prices will result in \$0$0 annual profit? enter the lower price first.