Answer:
"I can find the maximum or minimum by looking at the factored expression of a quadratic function by reading off its roots and taking the arithmetic average of them to obtain the 
-coordinate of the quadratic function, and then substituting that value into the function."
Step-by-step explanation:
Because of the symmetry of quadratics (which is the case here because we have two factors of degree 1, so we are dealing with a <em>polynomial</em> of degree 2, which is a fancy way of saying that something is a quadratic), the -coordinate of the extremum (a fancy way of saying maximum or minimum) is the (arithmetic) average of the two roots.
In the factored form of a quadratic function, we can immediately read the roots: 3 and 7. Another way to see that is to solve 
, which gives 
(the 'V' stands for 'or'). We can take the average of the two roots to get the -coordinate of the minimum point of the graph (which, in this case, is 
).
Having the -coordinate of the extremum, we can substitute this value into the function to obtain the maximum or minimum point of the graph, because that will give the 
-coordinate of the extremum.
Answer:
y=16x
Step-by-step explanation:
So, you are given the equation as if y=total distance the earth travels in x minutes. If you are given that you travel 80 miles in 5 minutes, you can plug these value into the variables they are representing and solve for the constant.
Visual:
y=xk y=miles x=minutes k=constant
Plug in your values and you get:
80=5k
Now, you solve for k by diving 5 on both sides, which leaves you with k=16.
Now you plug your value for k into the original equation, leaving you with y=16x
This would simply be y=8x. Which is not one of the options. Are you sure that is the function?
So x willl equal to 6 because 5(2x-8) is 10x-40=20 then you add 40 to 40 wich will equal nothing . u gonna have to eliminate 40 then you 40 to 20, wich is 60 what you gonna need to do is 10x=60
__ __ 60/10 is 6
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