Answer: 6 hours
Step-by-step explanation: to find the amount of the first DJ, use the equation 120+25x=y. For the second, use 45x=y. Then, substitute y for the first DJ. 120+25x=45x. Now, solve for x.
120+25x=45x
Subtract 25x from both sides
120=20x
Divide bith sides by 20
6=x