Why can you multiply or divide both terms of a ratio by the same number without changing the value of the ratio?

Avegetable garden and a surrounding path are shaped like a square together are 12 ft wide. the path is 1 feet wide. if one bag of gravel covers 8 square feet, how manu bags are needed to cover the path? round your answers to the nearest tenth.

Each cookie sells for $0.50 sam spent $90 on baking supplies and each cookie cost $0.25 to make how many cookies does sam need to sell before making a profit formula: sales> cost

Can someone me with my math problems i have a bunch. i will give brainliest and lots of pleeeaaasssee