If xy=0
assume that at least x or y=0
3(x-3)=0
therefor
3=0 or x-3=0
3=0 is false
therefor
x-3 mus equal zero
x-3=0
add 3 to both sides
x=3
Okay. So we have to do division, because you're dividing 4 1/4 (17/4) tablespoons of medicine by 5 doses. The formula for multiplying fractions is keep, change, flip. 17/4 * 1/5 is 17/20. 17/20 tablespoon of medicine is supposed to be taken in each dose.