What is the highest common factor of 20 and 30

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

Abcd is a square. what is the measure of angle bac

3x+2y=8 y=x-6 in substitution method