Answer:
V = pi*x^2*(18x - 45)
Step-by-step explanation:
If the diameter is 6x and the height is 2x + 5, we know that the radius is 3x.
Plugging this info into the volume-of-a-cylinder formula V = pi*r^2*h, we get:
V = pi*(3x)^2*(2x - 5), or V = pi*(9x^2)(2x -5), or:
V = pi*(18x^3 - 45x^2), or V = pi*x^2*(18x - 45)
<span>-2x^2 + 10x + 9 =0
multiply whole equation by -1
2x^2 -10x -9 =0
(sqrt2x)^2 -2(sqrt2x)(5/</span>sqrt2) -9=0
add (5/sqrt2)^2 on both sides
(sqrt2x)^2 -2(sqrt2x)(5/sqrt2) + (5/sqrt2)^2-9=(5/sqrt2)^2
a^2-2ab+b^2=(a-b)^2
(sqrt2x - 5/sqrt2)^2=(5/sqrt2)^2+9
(sqrt2x - 5/sqrt2)^2=21.5
taking squareroot on both sides
sqrt2x - 5/sqrt2 = +-4.64
so
sqrt2x - 5/sqrt2 = +4.64 or sqrt2x - 5/sqrt2 = -4.64
sqrt2x = 4.64 + 5/sqrt2 sqrt2x = -4.64 + 5/sqrt2
sqrt2x =8.18 sqrt2x = -1.1045
x=8.18/sqrt2 x= -1.1045/sqrt2
x=5.78 x=-0.781
Answer:
4
Step-by-step explanation:
The mean is the average of a data set. It can be found by adding up all of the values in a data set and then dividing it by the number of values in the data set.
The values in this data set;

The number of values in this data set,

Find the mean;


Answer:
The area is approximately 1256.64 The circumference is approximately 125.66
Step-by-step explanation:
This is because to find the area of a circle you square the radius and multiply by Pi. To find circumference, you can multiply the Diameter (twice radius) by Pi.
The answer is A.
I think so because each one of them agrees with 20x and 15