I need help on these two problems

-0.5y=-50
3y-7=8

Acarnival sold tickets for $1.50 for adults and $1.00 for students. there were 54 tickets sold for a total of $70.50. write a system of equations to represent the number of adult tickets, x, and the number of student tickets, y. find the solution and explain what it means. i'll you if you me

Aflower has 26 chromosomes. to create a new flower, how many would a sperm cell have what is called?

Why is causation so much more difficult to prove than correlation?