Help please! I’m bad at math

Tina practice piano for 15 hours last month and 45 hours this month use multiplication to write a statement comparing me i was tina practice during the two months use addition to write a statement comparing the hours tina practice during the two months

This is so hard and it’s for a test

Awasher and a dryer cost $701 combined. the washer costs $51 more than the dryer. what is the cost of the dryer?