When two fraction refer to the same whole and have the same denominators , explain why you can compare only the numerators

Because two fractions are equal fractions when they represent the same part of a whole. if denominators are different you need to first equal the denominator then further proceed to solve

A: 18/15b : 7 - -8 = 15 , 12 - -6 = 18 the y variable always goes over the x variables, c : same thing a