Question

Working his way through school, Joe works two part-time jobs for a total of 18 hours a week. Job A pays $5.70 per hour, and Job B pays $6.80 per hour. How many hours did he work at each job the week that he made $111.40?

Answer 1

A = 14.2/1.1 hours

B = 5.091 hours

Explanation:

Formulate 2 simultaneous equations

5.7A + 6.8B = 111.40..........(1)

A +B =18...............................(2)

Multiply each item in (2) by 5.7 to get

5.7A + 5.7B = 97.2............(3)

subtract (1) - (3) on each side

5.7A -5.7A + 6.8B - 5.7B = 111.40 -97.2

1.1B = 14.2

B = 14.2 /1.1

to get A use equation (2)

A = 18 - B

A = 18 - 14.2/1.1 = 5.091

Answer 2

Answer:in the week , he worked 10 hours at Job A and 8 hours at job B

Explanation:

Let x represent the number hours that Joe worked at job A in a week.

Let y represent the number of hours that Joe worked at job B in a week.

Working his way through school, Joe works two part-time jobs for a total of 18 hours a week. This means that

x + y = 18

Job A pays $5.70 per hour, and Job B pays $6.80 per hour. He made a total of $111.4 working at each job during the week. It means that

5.7x + 6.8y = 111.4 - - - - - - - - - -1

Substituting x = 18 - y into equation 1, it becomes

5.7(18 - y) + 6.8y = 111.4

102.6 - 5.7y + 6.8y = 111.4

- 5.7y + 6.8y = 111.4 - 102.6

1.1y = 8.8

y = 8

x = 18 - y = 18 - 8

x = 10