how do you set this problem up to solve it

Question

 Julie works two part-time jobs for a total of 37 hours a week. Job A pays $6.20 per hour, and Job B pays $7.40 per hour
hours a week. how many hours did she work at each job the week that she  made $249.80?

Answer 1

a + b = 37 -------> a = 37 - b

6.2a + 7.4b = 249.8

 

6.2(37 - b) + 7.4b = 249.8

229.4 - 6.2b + 7.4b = 249.8

1.2b = 20.4

b = 17

 

a = 37 - 17 = 20

Answer 2

Hi Hannah,

 

If we let the hours she works at job A be x, then the hours she works at job B = 37-x

The amount of money she makes working at each job can be written as time times pay rate as below

6.20*x + 7.40*(37-x) = 249.80

6.2x + 273.8 - 7.4x = 249.8 (I got rid of the zeros after the decimal point since they have no value)

-1.2x = -24

x = 20 hours (she worked at job A)

37-20 = 17 hours she worked at job B