On which interval is the function decreasing

Choice B) pi/4 < x < 3pi/4

Graph the function using a graphing calculator. I used desmos which is a free online tool. The graph is shown below as the red curve. The blue region represents the region in which the red curve is going downhill as you read from left to right on the interval from x = pi/4 to x = 3pi/4.

the correct answer is the second option

answer: (c) m∠qpo + (2x + 16)° = 180°

step-by-step explanation:

the opposite angles of a quadrilateral are supplementary.

so, ∠o + ∠q = 180°   and   ∠p + ∠r = 180°

since ∠r = 2x + 16°, we can use substitution as follows:

∠p + ∠r = 180°

∠p + (2x + 16)° = 180°