Let x represent radius of circle.
We have been given that the height of a cylinder is twice the radius of its base. So height of cylinder would be
.
Now we will use volume of cylinder formula to our given problem.
, where,
r = Radius of base of cylinder,
h = Height of cylinder.
Upon substituting our given values, we will get:


Therefore, our required volume expression would be
.
Answer:
When m = 6, 5m - 4 = 26.
Step-by-step explanation:

Substitute:

Multiply:

Subtract:

When m = 6, 5m - 4 = 26.
Remark
There is no short way to do this problem and no obvious way to get the answer other that to solve each part.
Solve
A
Multiply by 2
x + 1.6 = 2(x + 0.1) Remove the brackets
x + 1.6 = 2x + 0.1*2
x + 1.6 = 2x + 0.2 Subtract x from both sides
1.6 = x + 0.2 Subtract 0.2 from both sides
1.6 - 0.2 = x
1.4 = x
Circle A
B
Subtract 2x from both sides.
3x - 2x = 1.4
Circle B
C
Remove the brackets.
4x + 6 = 2x - 6 Add 6 to both sides
4x + 12 = 2x Subtract 4x from both sides.
12 = -2x Divide by - 2
12/-2 = x
x = - 6 Don't circle C
D
I'm going to be very scant in my solution of this. You can fill in the steps.
3x = 4.2
x = 4.2/3
x = 1.4
Circle D
Answer: 78.5 units^2
Step-by-step explanation:
The area of the circle is equal to pi*radius^2.
The diameter is double the radius, which means the radius is 10/2 = 5.
Therefore, the area is pi*5^2 = 25pi.
We use 3.14 for pi and we get 25*3.14 = 78.5 units^2
-3(b - 7)
Distributive property
-3*b = -3b
-3*7 = -21
-3b + 21
Answer: -3b + 21