Serious help to solve this solving trigonometric identities

[Ivory James]

I have no clue how to go on with this question despite substituting with the identities besides that I'm lost.

Solve: cos x = - cos 2x - 2 sin 2x + sin x + 1
for x ∈ [- 180, 180]
the 180's are in degrees

Thank you so much in advance

 

[lev888]

I have no clue how to go on with this question despite substituting with the identities besides that I'm lost.

Solve: cos x = - cos 2x - 2 sin 2x + sin x + 1
for x ∈ [- 180, 180]
the 180's are in degrees

Thank you so much in advance

Post your work.

 

[Steven G]

You need to try something!
Can you get all the angles to just be x (no 2x's)?