Not so sure about the second one, but the first one is pretty simple:
The area of a circle = pi x radius^2
Since you need to find the area of the entire dvd, I'm assuming they mean if the hole in the center wasn't there, so add that to the diameter.
12+1.5 = 13.5
Half of the diameter is the radius, so half of 13.5 = 6.75
Now, multiply pi (3.14) by the radius, but have the radius squared. You'd write the equation like this:
3.14 x 6.75^2 (or on paper, the ^2 would be a small two diagonal from the 5)
Actual answer: 143.06625
You can round that to 143.
Just put them in order from least to greatest and find out in between which number to put them . For example put 24 between 20 and 25.
Hope that helps .
Answer:
x = -1, y = 1
Step-by-step explanation:
6 + 4x - 2y = 0 (1)
-3 - 7y = 10x (2)
From (1)
6 + 4x - 2y = 0 (1)
4x - 2y = -6 (3)
From (2)
-3 - 7y = 10x (2)
10x + 7y = -3 (4)
4x - 2y = -6 (3)
10x + 7y = -3 (4)
Using elimination method
Multiply (3) by 10 and (4) by 4 to eliminate x
40x - 20y = -60
40x + 28y = -12
28y - (-20y) = -12 - (-60)
28y + 20y = -12 + 60
48y = 48
y = 48/48
y = 1
Substitute y = 1 into (3)
4x - 2y = -6 (3)
4x - 2(1) = -6
4x - 2 = -6
4x = -6 + 2
4x = -4
x = -4/4
x = -1
x = -1, y = 1
The value of x in the equation is -1
Answer:
The volume is decreasing at the rate of 1.396 cubic inches per minute
Step-by-step explanation:
Given
Shape: Cone
--- rate of the radius
--- rate of the height


Required
Determine the rate of change of the cone volume
The volume of a cone is:

Differentiate with respect to time (t)

Substitute values for the known variables









The volume is decreasing at the rate of 1.396 cubic inches per minute
Answer:
31
Step-by-step explanation:
Evaluate following the order set out in the acronym PEMDAS
That is parenthesis, exponents, multiplication, division, addition, subtraction
Given
(5 + 1)² - (11 + 3² ) ÷ 4
= 6² - (11 + 9) ÷ 4
= 36 - 20 ÷ 4 ← division before subtraction
= 36 - 5
= 31