14x - 129 (I think I’m so sorry if it’s wrong)
D=325. u multilply 5 times 65 and thats the answer u get
Answer: 
<u>Step-by-step explanation:</u>
Note the following identities: tan² x = sec²x - 1

tan² x + sec x = 1
(sec² x -1) + sec x = 1
sec² x + sec x - 2 = 0
(sec x + 2)(sec x - 1) = 0
sec x + 2 = 0 sec x - 1 = 0
sec x = -2 sec x = 1
