<span>It could be C. If the blade spends twice in a minute, it would be 30 seconds. 30=2pi/B=pi/15. </span>
-4d + 2(3+d)= -14
distribute the 2(3+d)
-4d + 6+ 2d= -14
Combine the like terms
-4d + 2d + 6= -14
-2d + 6 = -14
subtract 6 to -14
-2d = -20
divide by -2
d= -20/-2
d= 10
Check your answer
-4(10) + 2(3+ 10) = -14
-40 + 6 + 20
-40 + 26= -14
(n-4)(n+11) so pretty much B
It should be noted that the angle at the center of the circle is twice the angle at the circumference.
<h2>
Circle Theorem</h2>
It should also be noted that the angle in a semicircle is a right angle. Angles that are in the same segment are equal.
Furthermore, the opposite angle that is in a cyclic quadrilateral sum is 180°. The angle between the chord and the tangent is also equal to the angle in the alternate segment.
Learn more about circles on:
brainly.com/question/24375372