18 = 2/5 f what is the solution

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 is the missing step in this proof ?

How to use order of operation in 20 divide by 4 multiply 5 = 1