Given:
Trisha uses 3 cups of sugar for every 2 teaspoons of baking soda to make a batch of cookies.
To find:
The equation that she should use to find the number of teaspoons of baking soda, x, needed if she uses 9 cups of sugar.
Solution:
Let the number of teaspoons of baking soda be x, that is needed if she uses 9 cups of sugar.
For every 2 teaspoons of baking soda Trisha uses 3 cups of sugar.
For every 1 teaspoons of baking soda Trisha uses [tex]\dfrac{3}{2}[/tex] cups of sugar.
For every x teaspoons of baking soda Trisha uses [tex]\dfrac{3}{2}x[/tex] cups of sugar.
Since she uses 9 cups of sugar for every x teaspoons of baking soda, therefore,
[tex]\dfrac{3}{2}x=9[/tex]
Multiply both sides by 2.
[tex]3x=18[/tex]
Divide both sides by 3.
[tex]x=6[/tex]
Therefore, the required equation is [tex]\dfrac{3}{2}x=9[/tex] and the number of required teaspoons of baking soda is 6.
