How is the process of finding equivalent ratios like the process of finding equivalent fractions

It is the same process because ratios and fractions are the same. For example, ratio 1 : 3 can be written in the form of fractions as 1/3. Ratio 1 : 4 is fraction 1/4, and so on. So, if you want to find equivalent ratios, you will use the same process as for finding equivalent fractions.

The answer is 15×7=105therefore, 105×5=525 miles

Aand b are correctly balanced reactions. they have the same number of atoms in both sides of the reaction