kyle uses 3 cups of sugar for every 2 teaspoons of baking soda to make a batch of cookies which proportion could he solved to find x, the number of teaspoons of baking soda needed for 9 cups of sugar.
3/2=x/9
3/2= 9/x
9/2=x/3
9/2=3/x
Therefore, the proportion to solve for x would be:
3/2 = x/9