Answer: the answer is 1
Step-by-step explanation:
I'll assume those are squares. We know D is an identity:

Dividing through by


That's A.
Dividing the original through by


Not quite B, wrong sign on tangent.
C has the wrong sign on cosine squared as well.
Identities: A & D
Answer for this question: X < -20
Answer: 5x+25y-50
Step-by-step explanation: Hope this help :D
5(x+5y-10)
=(5)(x+5y-10)
=(5)(x)+(5)(5y)+(5)(-10)
=5x+25y-50