How do i solve ratio and rate problems using equivalent ratios or cross products?

The surface area (sa) of a cube with a as the length of each of its sides is given by the formula . if the surface area is known, how can you rewrite the formula to find its side?

Ataxi cab charges $1.75 for the flat fee and $0.25 for each time. write an in equality to determine how many miles eddie can travel if he has $15 to spend.

Acircular city park has a sidewalk directly through the middle that is 111 - feet long. if each bag of fertilizer covers 50 square feet, then determine how many bags of fertilizers the parks and recreation department needs to use to cover the circular park. ignore all the sidewalks around and through the park.