Parallel and perpendicular lines
question: find the slope of a line perpendicular to 3x + 5y = 15
answers: a. -5/3 b. -3/5 c. 3/5 d. 5/3
if someone could me with this subject i would greatly appreciate it!

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

Precalculus question, image attached.

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