Answer:
diameter = 2.5 feet
Step-by-step explanation:
Circumference of a circle is given as C = πd
Circumference of the tree trunk = 7.85 ft
π = 3.14
Diameter of the tree trunk = d
Thus:
7.85 = 3.14*d
Divide both sides by 3.14
7.85/3.14 = 3.14*d/3.14
2.5 = d
d = 2.5 ft
That question is accompanied by these answer choices:
<span>A. The scale is accurate but not precise.
B. The scale is precise but not accurate.
C. The scale is neither precise nor accurate.
D. The scale is both accurate and precise.
Then you need to distinguish between accuracy and precision.
Accuracy refers to the closeness of the measure to the real value, while precision, in this case, refers to the level of significant figures that the sacle report.
The fact that the scale reports the number with 4 significant figures means that it is very precise, but the fact that the result is not so close to the real value as the number of significan figures pretend to be, means that the scale is not accurate.
So, the answer is that the scale is precise but not accurate (the option B</span>
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.