Answer:
5.19 for the roast beef & 2.39 for the cheese. 7.58$
10.00$-7.58$=3.42$
-5(-2b-1)
Collect like terms and simplify
(Multiply the number outside the bracket with the ones in the parentheses/bracket)
(-x-)= +
(+x+)= +
(-x+)= -
(+x-)= -
Basically same signs multiplied = +
Different signs multiplied = -
-5(-2b)= 10b
-5(-1)=5
10b+5 is your answer
ANSWER
The exponential function is

EXPLANATION
Let the exponential function that is represented by the values in the table be of the form,

The points in the table must satisfy this exponential function.
We substitute the point,

to get,

This implies that,


Our function now becomes,

We gain, plug in another point yo find the value of b too.
Let us substitute

This implies that,

We divide through by 3 to obtain,

Therefore the function is,

The correct answer is A.