Answer:
She worked for 55 hours
Explanation:
Given
![Hourly\ Rate = \$4.50](https://img.qammunity.org/2021/formulas/mathematics/high-school/9yawhnmhmqaeimfj4mtowtds2xfskdprhr.png)
![Tips = \$156](https://img.qammunity.org/2021/formulas/mathematics/high-school/7h9yzrzciebm47yvbdv8l1v6kk4bgkfa5y.png)
![Earnings = \$403.50](https://img.qammunity.org/2021/formulas/mathematics/high-school/wwvubmrn8esfwkudu074ujrznccq51045l.png)
Required
Determine the number of hours worked
Represent the number of hours with h.
If 1 hour = 4.50
h hours = 4.50 * h
Hence:
Her earnings can be represented as
![Earnings = Tips + Total\ Hourly\ Wages](https://img.qammunity.org/2021/formulas/mathematics/high-school/q5ijopuhxz81ryyuysqnhu7g13ejm5y1fa.png)
This gives
![403.50 = 156 + 4.50 * h](https://img.qammunity.org/2021/formulas/mathematics/high-school/to36wrx0tl5wtma7qng1o155znvt4300t0.png)
![403.50 = 156 + 4.50h](https://img.qammunity.org/2021/formulas/mathematics/high-school/zj9j8gmyrgp7ykccka7q09b8dgui10d7pg.png)
Collect Like Terms
![4.50h = 403.50 - 156](https://img.qammunity.org/2021/formulas/mathematics/high-school/mi1i9s4fgy9kc6vkvqyhra0u22vqqymk3q.png)
![4.50h = 247.50](https://img.qammunity.org/2021/formulas/mathematics/high-school/n88yd4edr1v7qoylrqh3aa67ighpffjpcy.png)
Solve for h
![h = 247.50/4.50](https://img.qammunity.org/2021/formulas/mathematics/high-school/tgfaknq1f6ljr73lhvyl7e4eg0yr7004ag.png)
![h = 55](https://img.qammunity.org/2021/formulas/mathematics/high-school/prdze41bt9jpokhyw0sht2igyzhl4p8nb3.png)
Hence:
She worked for 55 hours