Make the mixed number improper ( multiply whole number by denomentaor then add that number to the numerator and put it over the orignial denominator) to get this (15/2)/(21/4)=x/9 we know that a/b/c/d = a/d * d/c so 15/2*4/21=60/42=x/9 simplify 30/21=x/9 10/7=x/9 10/9*9/1 (10/9*9) =x 90/9=x 10=x
