Seeing the graph from desmos.com, we know there is only one place where the graph will go up then down, or down then up given that the maximum exponent of x is it squared. That place, as seen, is -0.375 for the minimum as it goes down then up. There's no maximum in sight :(
Answer: 
Step-by-step explanation:
You can use the following formula:

You can say that "T" is the time (in minutes) for both faucets working together, "A" is the time (in minutes) for cold water faucet working alone and "B" is the time (in minutes) for hot water faucet working alone.
Based on the data given in the exercise, you can identify that:

Therefore, substituting these values into the formula and solving for "B", you get that this is:

Answer:
A)(7,-9)
Step-by-step explanation:
we know x=7
so put it in the equation
y= -2(7)+5
y=-9
we always put the x coordinate first and then the y coordinate so the answer is (7,-9)
Round all of the numbers to the nearest 10 then solve the problem like normal
The volume is proportional to the cube of the radius:
4^3=64
The volume will be 64 times the original value!