Simplify: -5g + 2h - 3g + g -2h

Can someone me out here number 4 plz

Hurrya vegetable garden and a surrounding path are shaped like a square that together are 11ft wide. the path is 2ft wide if one bag of gravel covers 9 square feet how many bags are needed to cover the path

Hurry if the population of of an ant hill doubles every 10 days and there are currently 100 ants living in the ant hill what will the ant population be in 20 days