Solution:
The number of hours worked for the month is
The amount earned as a tutor for one hour is
The amount earned as a waitress for one hour is
The number of hours Rachel worked as a tutor is
Let the number of hours she worked as a waitress be
The equation representing the total hours worked for the month will be
The amount of money Rachel earned as a tutor this month will be calculated as
The amount of money Rachel earned as a waitress this month will be calculated as
The expression to represent the combined total earned this month will be
Substitute equation (1) in equation (2) above, we will have
Hence,
The expression for the combined total she earned this month = 1365 -6t