C. 452.16
use formula pir^2
12^2 = 144
144 x 3.14 = 452.16
I used pi as 3.14
Answer:
1 Multiply the first equation by -1 then add the equations together
3. Multiply the second equation by -1 then add the equations together
4. Multiply the first equation by -2 then add the equations together
5. Multiply the first equation by 2 the second by -1 then add the equations together
Step-by-step explanation:
x+y = 7
2x+y = 5
1 Multiply the first equation by -1 then add the equations together
-x+-y = -7
2x+y = 5
---------------
x =-2 then solve for y
2. Multiply the second equation by -1 first equation by -1 then add the equations together
-x+-y = -7
-2x-y = -5
---------------
-3x -2y = -12
Still have both variables
3. Multiply the second equation by -1 then add the equations together
x+y = 7
-2x-y =- 5
----------------------
-x = 2
4. Multiply the first equation by -2 then add the equations together
-2x+-2y = -14
2x+y = 5
--------------
-y = -9
5. Multiply the first equation by 2 the second by -1 then add the equations together
2x+2y = 14
-2x-y = -5
--------------
y = 9
Answer:
400 points for you
Step-by-step explanation:
Answer: 
Step-by-step explanation:
For this exercise you need to remember the following Trigonometric Identity:
You must observe the figure given in the exercise.
You can notice that the given triangle EFG is a Right triangle (Right triangles are defined as those triangles that have an angle that measures 90 degrees).
So, you can identify in the figure that:
So, knowing these values, you can substitute them into and then you must evaluate (Remember to round the result to the nearest hundreth).
Therefore, through this procedure you get:
