Let 'c' be the number of cones that the coach can buy. Since each ice cream cone costs $2.80, then we have the following expression:
![2.8c](https://img.qammunity.org/2023/formulas/mathematics/college/1x2ajco8hwwml3xsbv85zusp1q5eqthu9n.png)
Now, the coach has $42, then we can write the following equation:
![2.8c=42](https://img.qammunity.org/2023/formulas/mathematics/college/2y8rfuuirg9lc0p0wo7fxzks9fboz4a4c7.png)
To solve for 'c', we just have to move the coefficient 2.8 to the right side doing its opposite operation: division:
![\begin{gathered} 2.8c=42 \\ \Rightarrow c=(42)/(2.8)=15 \\ c=15 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/3q8qrsvlgoip8rjoemx29be3b6429lusq1.png)
therefore, the coach can buy 15 ice cream cones with $42