C. Because complementary angles are two angles whose sum equals 90 degrees so do 90-40=50 then 50x2= 100
X=11, set 10x+5x+15=180
15x+15=180, subtract 15 from 180= 165, then divide 165 by 15
Answer:
-cos(2x)
Step-by-step explanation:
I did trig last year and tutor a trig class this year :)
Answer: The answer is (x+2)(x-4)(x-4)
Or as a short form you can write it as 
Step-by-step explanation:
Answer is very lengthy but I am 100% sure that's the correct answer