What is the additive inverse of 34-1.5d

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

Find the solution of this system of equation -7x+y=-20 9x-3y=36

What is the point of inflection for the function f(x)=2cos4x on the interval (0, pi/2)