Posted by mary on .
Sally works at a grocery store. In one week she earned $390 for working 47 hours, of which 7 hours were overtime. The next week she earned $416 for working 50 hours, of which 8 hours were overtime. What is Sally's hourly overtime rate in dollars per hour?

algebra 
Reiny,
let her regular rate be $x per hour
let her overtime rate be $y per hour
first week: 40x + 7y = 390
2nd week: 42x + 8y = 416
1st equat x 8 > 320x +56y = 3120
2nd equt x 7 > 294x + 56y = 2912
subtract
26y = 208
y = 8
so her overtime rate is $8 per hour