tom sold half of his comic books and then bought 6 more .he now has 36 comic books. how many did he begin with?

This is so hard and it’s for a test

Consider a bag that contains 220 coins of which 6 are rare indian pennies. for the given pair of events a and b, complete parts (a) and (b) below. a: when one of the 220 coins is randomly selected, it is one of the 6 indian pennies. b: when another one of the 220 coins is randomly selected (with replacement), it is also one of the 6 indian pennies. a. determine whether events a and b are independent or dependent. b. find p(a and b), the probability that events a and b both occur.

Write 5(6x+4)-2(5x-2) in the form a(bx+c) where a,b and c integers and a> 1