We want to find hourly pay for Mandy, given that his cousin earns 30% more, and last week they worked 23 and 27 hours, respectively; and that together they earned $493.85.
Let us denote by x the hourly pay of Mandy, then we have the equation:
Where the first summand of the right-hand side corresponds to 27 hours done by Mandy's cousin, multiplied by the value of hourly pay and adding the 30% that she earns. And the second summand: 23x corresponds to the hours worked by Mandy multiplied by the hourly pay.
We isolate x:
This means that the hourly pay that Mandy will receive will be $8.5.