Leah worked a total of 30 hours at two jobs last week. Her combined pay from the jobs was $240. She earned $9 per hour working at the movie theater and $6 per hour babysitting. How many hours did she spend babysitting? Which system of equations would solve this problem? M= number of hours at movie theater B= number hours spent babysitting OM+B= 30: M + B = 240 OM+B=240: 9M + 6B = 30 OM+B=30: 9M + 6B - 240 OM + B = 30; 15(M+B)-240
