Does supplementary angles have a sum of 90

6n^2-7n-75=0 solve by quadratic formula

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

Prove that quadrilateral is a rhombus.