Answer:
The expression is:
![\text{total thickness} = \text{cookie thickness} + \text{frosting thickness}](https://img.qammunity.org/2021/formulas/mathematics/high-school/5tuaethw6ajw7yu1ijo10wutu4gtjs9neq.png)
The thickness of the cookie is:
cm
Explanation:
The cookie is formed by two layers, the cookie and the frosting. So if we want to know the total thickness of the cookie and frosting we need to sum the thickness of each layer as shown below:
![\text{total thickness} = \text{cookie thickness} + \text{frosting thickness}\\\text{total thickness} = (9)/(10) + (33)/(100)\\\\\text{total thickness} = (10*9 + 33)/(100)\\\\\text{total thickness} = (123)/(100) \text{ cm}](https://img.qammunity.org/2021/formulas/mathematics/high-school/kypj5pfo830l9gqxznfydjg1smsptkbz7d.png)
The expression is:
![\text{total thickness} = \text{cookie thickness} + \text{frosting thickness}](https://img.qammunity.org/2021/formulas/mathematics/high-school/5tuaethw6ajw7yu1ijo10wutu4gtjs9neq.png)
The thickness of the cookie is:
cm