Because it is like having a unit of measurement that is set
lets say that in a certain country, one serving of bread is 1/2 of the standard loaf
and if you have 3 servings, you have 3/2 loaf so the bottom number tells you how many parts out of 1 whole you have
Step-by-step explanation:
5x−4=5
1 Add 44 to both sides.
5x=5+4
5x=5+4
2 Simplify 5+45+4 to 99.
5x=9
5x=9
3 Divide both sides by 55.
x=\frac{9}{5}
x=
5
9