A company decides to drain the water heater to flush out sediments. The water heater has a capacity of 500 gallons. It drains 100 gallons in 20 minutes. After 20 minutes, they open another drain valve and it drains 200 gallons in the next 20 minutes. The drain valves are closed for 10 minutes, while the workers take a break and then the water heater is drained until the water heater is completely empty. What are the domain and the range of this relation?

≤ y ≤ 70 and 0 ≤ x ≤ 500

Step-by-step explanation:

In this relation we have two things to analyze, the number of gallons of water in the heater, that is 500 gallons, and the time that it took to empty the heater.

Let's count the time.

First, there are 20 minutes in wich 100 gallons are drained.

then, another drain valve is opened, so in 20 minutes they drain 200 gallons of water.

now, the wait for 10 minutes.

Now there are 200 gallons remaining, so the workers must wait for the other 20 minutes to drain the 200 gallons remaining.

The total amount of time is 70 minutes.

So if we have a relationship of water in the heater vs time, where X is the water remaining and Y is the time, the correct domains are:

Y from 0 minutes to 70 minutes

X from 0 gallons to 500 gallons  

So the correct options are C and E.

0 ≤ y ≤ 70 and 0 ≤ x ≤ 500

there are many solutions.

step-by-step explanation:

step 1: simplify both sides of the equation.

4x+6=4x^2+10x−4

step 2: subtract 4x^2+10x-4 from both sides.

4x+6−(4x^2+10x−4)=4x^2+10x−4−(4x^2+10x−4)

−4x^2−6x+10=0

step 3: factor left side of equation.

−2(2x+5)(x−1)=0

step 4: set factors equal to 0.

x=-5/2 or x=1