What is the greatest common factor of 20, 45x

Peaches cost $4.29 per pound. find the cost of two and a quarter pounds of peaches.

You are remodeling your kitchen. you’ve contacted two tiling companies who gladly told you how long it took their workers to tile of a similar size jim completed half the floor in 8 hours. pete completed half of the other floor in 7 hours. if pete can lay 20 more tiles per hour than jim, at what rate can jim lay tiles

What are “like terms”? why can we only add like terms?