Answer:
The study is an observational study.
Step-by-step explanation:
Observational study: In research methods, the term "observational study" is determined as one of the different studies that are being conducted by the researchers to observe or study the effects of a specific risk factor, treatment, diagnostic test, or some other intervention in the absence of an effort to change which participants are being exposed and which is not being exposed to it.
Types: Cohort study and case-control study.
In the question above, the given statement represents the observational study.
Answer:
No.
Step-by-step explanation:
The Triangle Inequality Theorem states that this is not possible.
Answer:
Given the equation: 
A quadratic equation is in the form:
where a, b ,c are the coefficient and a≠0 then the solution is given by :
......[1]
On comparing with given equation we get;
a =3 , b = 10
then, substitute these in equation [1] to solve for c;

Simplify:

Also, it is given that the difference of two roots of the given equation is
i.e,

Here,
, ......[2]
.....[3]
then;

simplify:

or

Squaring both sides we get;

Subtract 100 from both sides, we get

Simplify:
-12c = -96
Divide both sides by -12 we get;
c = 8
Substitute the value of c in equation [2] and [3]; to solve 

or
or

Simplify:

Now, to solve for
;

or
or

Simplify:

therefore, the solution for the given equation is:
and -2.
Answer:
In the given options, 4+5 = 5+4 shows the best commutative property.
Step-by-step explanation:
One of the properties that can be applied on numbers is commutative property. Commutative property states that the order of the numbers on which any operation is being performed, can be swapped and the answer won't change.
Commutative property can be applied on addition, subtraction and multiplication.
<u>Commutative property of Addition:</u>
Commutative property of addition states that changing the order of adding two numbers does not change the result i.e. a+b = b+a
In the given options, 4+5 = 5+4 shows the best commutative property.