For #1, C. 1080, For #2, B. 7, For #10, I think its because of the reflexive property (honestly, Google it just to be safe) , And for #11, A Rhombus, Having trouble remembering why but I know its not a rectangle or square.
Answer:
a=-1/13c
Step-by-step explanation:
5a+8a=-c
13a=-c
a=-1/13c
55- 2v. Or also 55- (2xV)