Susan is filling two ponds in her back yard. She has to dig the hole, put the liner in, and fill the pond. The first pond holds 75 gallons of water and is filling at a rate of 7 gallons of water per hour. The second holds 115 gallons of water and is filling at a rate of 3 gallons of water per hour. Write an equation for each tank that represents the total amount of water in gallons in the tank, y, in terms of the number of hours, x, that the tanks are draining
I suspect you meant that they are draining. So, the two equations would be
y = 75-7x
and
y = 115-3x
for suitable domains of x.
To write the equation for each tank, we need to take into account the initial amount of water in the pond, as well as the rate at which the pond is filling.
For the first pond:
- The initial amount of water in the pond is 75 gallons.
- The pond is filling at a rate of 7 gallons per hour.
Therefore, the equation for the first pond can be written as:
y = 7x + 75
Where y represents the total amount of water in gallons in the first pond, and x represents the number of hours that the pond is filling.
For the second pond:
- The initial amount of water in the pond is 115 gallons.
- The pond is filling at a rate of 3 gallons per hour.
Therefore, the equation for the second pond can be written as:
y = 3x + 115
Where y represents the total amount of water in gallons in the second pond, and x represents the number of hours that the pond is filling.