Question

A bathtub that holds 43 gallons of water contains 18 gallons of water. You begin filling it, and after 5 minutes, the tub is full.
Enter an equation in standard form to model the linear situation.

Answer 1

the tub holds 43 gallons.....it contains 18.....(43 - 18) = 25....so it needs 25 gallons.....after 5 minutes, the tub is full.....so it fills at a rate of 25/5 = 5 gallons per minute

y = 5x + 18....where y is the total gallons and x is the number of minutes
but we need it in standard form....

y = 5x + 18
-5x + y = 18
5x - y = -18 <== standard form