If there are 50 floats in a parade how many ways can a first and second place trophy be awarded

Student price tickets to a movie are $1 and non student tickets are $2. 350 tickets are sold and the total amount made is $450. how many non student tickets were sold ? a) 100 b) 150 c) 200 d)250

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

How do i put 3(x+7) in distributive property