Respuesta :

Answer:

Step-by-step explanation:

first find the equations for both djs

dj alpha: y = 15x + 75

dj beta: y = 20x + 50

set the equations equal to each other

15x + 75 = 20x + 50

solve for x

25 = 5x

5 = x

after 5 hours the charges will be equal