Need with # 17 don't understand it

Which expression is the factorization of x^2+10+21

Officer brimberry wrote 32 tickets for traffic violations last week, but only 4 tickets this week. what is the percent decrease? give your answer to the nearest tenth of a percent.

Radials are weird[tex](14 \sqrt{6}) ^{2} [/tex]whats the answer and how do i solve pls