ANSWER
She worked 13 hours in Job A and 12 hours in Job B.
EXPLANATION
Eleanor works two part-time jobs.
Both jobs take a total of 25 hours a week.
Let the number of hours worked in Job A be x.
Let the number of hours worked in Job B be y.
This means that:
x + y = 25 _____(1)
Job A pays $6.00 per hour and Job B pays $6.80 per hour.
The total she made that week was $159.60.
This means that:
6 ^ x + 6.8 * y = 159.60
=> 6x + 6.8y = 159.6 _____ (2)
We have two simultaneous equations:
x + y = 25 _____ (1)
6x + 6.8y = 159.6 ___(2)
From (1), we have that:
x = 25 - y
Put that in (2):
6(25 - y) + 6.8y = 159.6
150 - 6y + 6.8y = 159.6
150 + 0.8y = 159.6
Collect like terms:
0.8y = 159.6 - 150 = 9.6
y = 9.6 / 0.8
y = 12 hours
Recall that:
x = 25 - y
=> x = 25 - 12
x = 13 hours
Therefore, she worked 13 hours in Job A and 12 hours in Job B.