If

, then you have


By the intermediate value theorem, there will be some number

such that

(i.e.

will have a root in

) if you can guarantee that

or

.
Since the coefficients

are all positive, then you know right away that

, so you need to have

in order for there to be such a

.
This means you need to have

which means (A) must be the answer.
Answer:
We will add 64 to both sides.
x=8±√20
Step-by-step explanation:
Here we are given the equation:

Now we take half of the coefficient of x and add it to x.
Coefficient of x is 16, half of 16 is 8.
Also we add square of 8 to both sides.
So new equation becomes:

Completing the square:

NOw let us simplify it to get the value of x.
Taking square root on both sides:

Bringing 8 to the right side:
x=8±√20
Answer:
Each marker will be exactly <u>103</u> miles apart.
Step-by-step explanation:
It is given that Ian wants to run 412 miles and has set up 3 markers the same distance apart.
Between the start and end of run, the 3 separate markers will divide the 412-mile distance into 4 equal segments.
So each segment = 412/4 = 103 miles
Each marker will be exactly <u>103</u> miles apart.