Answer:
$2.57
Step-by-step explanation:
divide 5,140 by 20,
5,140/20=257=2.57
Step-by-step explanation:
Exponential function is given by general form 
Where a and b are constants.
say a=1 and b=2 then we can write function as :

or 
To graph this or any exponential function, we just need to find some points then join them by a curved line.
Like plug x=0, 1, 2,... into above function and find points:
plug x=1

Hence point is (1,2)
Find more points similarly then graph them to get the graph as shown below:
First you multiply2x1 which is 2so now you know that y=2 right then you multiply 2 x 3=6 6=x for the last you wright YxX = 2 x 6=12.Hope I helped) this is your answer
Hello aysha123994 i am sure that it could be 17. if i am wrong forgive me
The answer is 96 square ft