let's say S is the age of the youngest sister. Then the age of the middle sister is S + 1, and the age of the oldest sister compared to the youngest is S + 2 we have54 = S + (S+1) + (S+2)which is the same as54 = 3S + 3 divide both sides by 354 / 3 = S + 118 = S + 1 subtract one from both sides17 = S check54 = 17 + 18 + 19 ( Hope this helps!!!!)
