Question

The lightest puppy in a litter weighs 9 ounces, which is 3/4 of the weight of the heaviest puppy. The equation 3/4 w + 9 can be used to find the weight w in ounces of the heaviest puppy. How much does the heaviest puppy weigh?

Answer 1

I think you meant to write
3/4W = 9
to get rid of the denominator, multiply both sides by the denominator.
3W = 36
now divide both sides by 3
W = 12
the answer is 12 ounces.