Answer: A
Step-by-step explanation:
(c-2d)(3c-2d)
= 3c^2 - 8dc + 4d^2
First we will convert those radian angles to degrees, since my mind works better with degrees. Let's work one at a time. First,

. If we start at the positive x-axis and measure out 315 we end up in the 4th quadrant with a reference angle of 45 with the positive x-axis. The side across from the reference angle is -1, the side adjacent to the angle is 1, and the hypotenuse is sqrt2. The cotangent of this angle, then is 1/-1 which is -1. As for the second one, converting radians to degrees gives us that

. Sweeping out that angle has us going around the origin more than once and ending up in the first quadrant with a reference angle of 30° with the positive x-axis. The side across from the angle is 1, the side adjacent to the angle is √3, and the hypotenuse is 2. Therefore, the secant of that angle is 2/√3.
.020 because it is 2 spots behind the decimal
Step-by-step explanation:
-28÷4=2
-7=2
= -7-2
= -9 is the correct answer..
2 wk --- 38 cm
3.5 wk --- x cm
x = 3.5 wk x 38 cm
---------------------
2 wk
x= 66.5 cm