For any direct variation, the equation is of the form y = kx, where k is the constant of proportionality.
Given the equation: f = 2.5w
The constant of proportionality is 2.5.
This means that the ration of the cups of flour to the cups of water used in the recipe is 2.5
It should be 20x because you multiply what’s on the outside (5) with what’s on the inside (4x) which Is also called distributing. :)
Let's label the original price of the dress as x. We know that

so that means that we can find x by dividing both sides by 5/8:

A simple rule for dividing fractions is 'Keep Change Flip'. You keep the first number/fraction the same, you change the ÷ to a × and you flip the second fraction. Through this rule, we can now solve the equation much more easily:

Therefore, the original price of the dress was $48
Answer:
480 calories
Step-by-step explanation:
4 ÷ 3/4= 5 1/3 servings
90 x 5 1/3= 480