add integers with like signs, add the integers with unlike sign's subtract the integers and copy the sign of the integers with greatest value give me a two example

Natasha spent 1 1/2 hours on the beach. she fell asleep for 3/4 of the time she was on the beach and then woke up with a terrible sunburn.how many hours was natasha asleep on the beach?

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

The number of branches on a tree demonstrates the fibonacci sequence. how many branches would there be on the next two levels of this tree? 13 | | | m branches