What is an equivalent expression for 2s+(-4s) and what are way for me to remember how to do equations like these

What are the equivalent ratios for 24/2= /3= /5.5=108/ = /15

Solve the following inequalities and show the solution on a number line. 3/4 (2x-7) ≤ 5

Cody started biking to the park traveling 15 mph, after some time the bike got a flat so cody walked the rest of the way, traveling 4 mph. if the total trip to the park took 6 hours and it was 46 miles away, how long did cody travel at each speed? solve using rate times time= distance