Answer:
Step-by-step explanation:
1.

c+9=±8
either c=8-9=-1
c=-8-9=-17
so c=-1,-17
D
2.
8x^2-3=2
8x^2=5


so A
3.

so D
or
Answer:
-3x + 8
Step-by-step explanation:
Simplify. combine like terms (terms with the same amount of variables).
Subtract -2x and x: -2x - x = -3x
-3x + 8 is your answer.
~
Answer:
2.6
Step-by-step explanation:
Hope this helps:) Have a good day!