Only those who actually know this ! i'm having a lot of trouble even doing this!

Which elements in the set below are integers? 12, –3⁄4,√ 25 , –7, √ 5 , 14⁄7, 9 a. 12, √ 25 , –7, 9 b. 12, √ 25 , –7, 14⁄7, 9 c. –3⁄4, 25 , √ 5 ,14⁄7 d. 12, –7, 9

What is the number 321,000,000 in scientific notation? also what is the number? ?

What is the factored form of the following expressions? d^2 – 13d + 36