How many hours did peter work at job a

Question

Peter worked par time jobs and earned 189 for working a total of 24 hours at both jobs. He is paid 6 per hour at job a. and 9 per hour at job .

Answer 1

You are given two equations

 

6a + 9b = 189

a + b = 24

 

solve the second for a

a = 24 - b

 

substitute this value for a in the first equation

 

6(24 - b) + 9b = 189

144 - 6b + 9b = 189

3b = 45

b = 15 hours

 

substitute tht value back into the second equation to solve for a

a = 24 - (15) = 9

 

Check by substituting the two values into the first equation

 

6(9) + 9(15) = 189

54 + 135 = 189

which is correct.