Let C represent The total charge, and let H represent the number of hours
For Jeweler A, we have the equation:
C = 120 + 18H
For Jeweler B, we have the equation:
C = 138 + 15H
To find the time they will charge the same amount of money, equate both equations and solve for H.
Thus, we have:
120 + 18H = 138 + 15H
Subtract 15H from both sides:
120 + 18H - 15H = 138 + 15H - 15H
120 + 3H = 138
Subtract 120 from both sides:
120 - 120 + 3H = 138 - 120
3H = 18
Divide both sides by 3:
Therefore, the two jewelers will charge the same amount of money after the 6 hours
ANSWER:
6 hours