15 points!

btw, you cannot answer in the 's just a

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

Two friends are reading books. jimmy reads a book with 21,356 words. his friend bob reads a book with one-and-a-half times as many words. which expression represents the number of words bob reads?

Y+ 2/y is it a polynomial in one variable or not? and if so, why?