Answer: 
Step-by-step explanation:
We can use the Rational Root Test.
Given a polynomial in the form:

Where:
- The coefficients are integers.
-
is the leading coeffcient (
)
-
is the constant term 
Every rational root of the polynomial is in the form:

For the case of the given polynomial:

We can observe that:
- Its constant term is 6, with factors 1, 2 and 3.
- Its leading coefficient is 2, with factors 1 and 2.
Then, by Rational Roots Test we get the possible rational roots of this polynomial:

Its same as powers of a whole number.
Lets take example
(1/2)²=1/2×1/2=1/4
We can write it in a different way (0.5)²=0.5×0.5=0.25
Now to solve this problem, all we have to remember is the
formula for calculating the linear speed given the radial speed, that is:
v = r w
where,
v = is the linear velocity or linear speed
r = is the radius of the circular disk = (1 / 2) diameter
= (1/ 2) (2.5 inches) = 1.25 inches
w = is the radial velocity (must be in rad per time) =
7200 rev per minute
Calculating for v:
v = 1.25 inches (7200 rev per minute) (2 π rad / 1 rev)
v = 56,548.67 inches / minute
Converting to miles per hour:
v = 56,548.67 inches / minute (1 mile / 63360 inches) (60
min / hour)
<span>v = 53.55 mile / hour</span>
A decameter is 10.9361 yards