Answer:
![0.75x+20=30](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gjsicrrij29633rem3l4x90s8lkt3gt9ts.png)
Explanation:
Let x be the no. of piles of leaves
Cost of raking leaves per pile= $0.75
Cost of raking leaves x piles= 0.75 x
Cost of mowing lawn = $20
His goal is to earn exactly $30 each time he mows a lawn and rakes leaves.
So, equation becomes :
![0.75x+20=30](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gjsicrrij29633rem3l4x90s8lkt3gt9ts.png)
Hence equation models Alan’s goal is
![0.75x+20=30](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gjsicrrij29633rem3l4x90s8lkt3gt9ts.png)