Ipicked up 15 shells and my brother picked up 3 more shells than i did. how many shells sis my brother and i picked altogether?

When are two distinct non vertical lines parallel

The price of a visit to the dentist is \$50$50. if the dentist fills any cavities, an additional charge of \$100$100 per cavity gets added to the bill. if the dentist finds nn cavities, what will the cost of the visit be?

How do i do this problem i don't know what to do can u