Step-by-step explanation:
2a - 7 - 6a = 9
- 4a - 7 = 9
- 4a = 16
a = -4
For this case, we have that by definition, the circumference of a circle is given by:

Where:
d: Is the diameter of the circle given by 2r, that is, twice the radius.
If we have a circle with a diameter equal to 8cm, then the circumference is given by:

ANswer:
Option C

Answer:
your answer is 9
Step-by-step explanation:
Just trust me!
Well this only simplifies to a smaller equation
so the answer would be...
2a²-9b²