Answer:
To figure out the change, we subtract the original temperature by the following after temperature.
18°F - original
-9°F - subsequent time after original
So we set up the equation;
18°F - (-9°F)
(Two negatives combine to form a positive)
18°F + 9°F
= <u>27°F</u> was the change in temperature.
As we have to solve for b, it means we have to isolate b
So first of all subtract 
from both sides
So we get
Now we need b , but its b^2 , so we can take square root on both sides.
taking square roots on both sides
Hence option B is correct
The answer would be the first one.
I find it easier to expand the equation (you still get the same answer).
= 2 * 7x + 2 * 3y + 2 * 3
= 14x + 6y + 6
Hope this helps!
Double is double, so you can solve
.. 2 = 1*e^(.08t)
and get the correct value of t.
Taking logs,
.. ln(2) = .08t
.. ln(2)/.08 = t ≈ 8.7 . . . . years
