A circle has a circumference of 20. It has an arc of length 9/2. What is the central angle of the arc in degrees?

81 degrees

Step-by-step explanation:

The circumference is given by

C = 2*pi*r

20 = 2*pi*r

Divide each side by 2pi

20/2pi = 2*pi*r/2pi

10/pi =r

We know the arc length can be found by

s =r theta  where theta is in radians

9/2 = 10/pi *theta

Multiply each side by pi/10 to isolate theta

9/2 * pi/10 = pi/10 *10/pi *theta

9*pi/20 = theta

We need to convert to degrees

9*pi/20 * 180/pi

81 degrees

x = -4

step-by-step explanation:

- 20 - 4(x + 3) = 4x

=> -20 - 4x - 12 = 4x

=> - 32 -4x = 4x

=> -32 = 4x + 4x

=> - 32 = 8x

=> -32/8 = x

=> -4 = x

answer: rolling a number cube and flipping a coin.

step-by-step explanation: