Question

Trisha uses 3 cups of sugar for every 4 cups of flour to make a batch of cookies. Which equation could be used to solve x, the number of cups of flour needed for 9 cups of sugar.

Answer 1

Answer: The number of cups of flour needed for 9 cups of sugar = 12.

Explanation:

Equation of direct proportion between two quantities x and y :

`(x_1)/(y_1)=(x_2)/(y_2)`

Let x= the number of cups of flour needed for 9 cups of sugar.

Put
`x_1=4,\ y_1=3,\ y_2=9, x_2=x`

`(4)/(3)=(x)/(9)\\\\\Rightarrow\ x=(9*4)/(3)\\\\\Rightarrow\ x=12`

Hence, the number of cups of flour needed for 9 cups of sugar = 12.