5x-17y=-6
rewrite equation in slope-intercept form

y=5/17x+6/17

Step-by-step explanation:

moving y to one side and x and the constant to one side you get 17y=5x+6

dividing through by 17 You get y=5/17x+6/17

The first pump fills one tank in 2 hours, so it works at a unit rate of (1 tank)/(2 hours) = 0.5 tanks/hour.

The second pump takes 3 hours to fill the same tank, so it works at a rate of (1 tank)/(3 hours) ≈ 0.33 tanks/hour.

Working together, the pumps can fill one tank at a rate of

(1/2 + 1/3) tanks/hour = (3/6 + 2/6) tanks/hour = 5/6 tanks/hour ≈ 0.83 tanks/hour

Then the time it takes both pumps to fill one tank is

(1 tank) / (5/6 tanks/hour) = 6/5 hours = 1.2 hours = 72 minutes