2 hours.
Mr. K (90x + 50)
enterprise (70x + 90)
90x + 50 = 70x + 90
you then move the x’s to one side and the other numbers to a diff side.
90x + 50 = 70x + 90
-70x = -70x
———————————
20x + 50 = 90
20x -50 = -50
20x = 40
after all the subtracting you divide
20x = 40
x = 2
2hours