Kathy works two part-time jobs for a total of 23 hours a week. Job A pays $5.70 per hour, and Job B pays $7.00 per hour. How many hours did she work at each job the week that she made $146.70? (Round to two decimal places if necessary.)

Kathy worked 11 hours at job A and 12 hours at job B, the week she made US$ 146.70.

Step-by-step explanation:

1. Let's review all the information given for solving this question:

Rate per hour of Job A = US$ 5.70

Rate per hour of Job B = US$ 7.00

Earnings received by Kathy during the week = US$ 146.70

Total time worked by Kathy during the week = 23 hours

Hours at job A = x

Hours at job B = 23 - x

2. Let's find how many hours Katy worked at each job:

This is the equation that we'll use:

5.70x + 7 (23 - x) = 146.70

5.70x + 161 - 7x = 146.70

- 1.3x = 146.70 - 161 (Subtracting 161 at both sides)

-1.3x = - 14.30

1.3x = 14.3 (Multiplying by - 1 at both sides)

x = 14.3/1.3 = 11 (Dividing by 1.3 at both sides)

Kathy worked 11 hours at job A and 12 hours at job B.

3. Proof of x = 11

5.70 x + 7 (23 - x) = 146.70

5.70 (11) + 7 (23 - 11) = 146.70

62.70 + 7 (12) = 146.70

62.70 + 84 = 146.70

146.70 = 146.70

The value of x = 11 is correct.