The ratio is 3:5, so if I added 12 more pieces of candy, I would get ?:17. 17 divided by 5 is 3.4, but I round to 3 because you can't have half a piece of candy. Then I times the original amount of gum(3) and 3. That equals 9, so 9 pieces of gum keeps the ratio equivalent.
if the end result of solving an equation is untrue, it means there is no number that will satisfy the equation, therefore the equation will have no solutions