Ok this is a pretty easy one.
2=22
3=20
4=18
Answer:

Step-by-step explanation:
You can make 1.4 as a fraction, and it will be the same but in a different form.
So, to make a decimal by a fraction, you make 1.4 into a whole number. 1.4 will be 14.
Now, the denominator will be 10.
So, when you simplify
, which is 
3: -27
4: 81
5: -243
All you need to do is plug in the numbers into the exponent spot.
Answer: a) c(x) = 0.124x + 1.1, b) 13 units
Step-by-step explanation: Revenue function = R(x) = 0.21x
Profit function = p(x) = 0.086 - 1.1
Cost function = c(x) =?
A)
Recall that profit = total revenue - total cost
Hence, total cost = total revenue - profit
c(x) = 0.21x - (0.086x - 1.1)
c(x) = 0.21x - 0.086x + 1.1
c(x) = 0.124x + 1.1
B)
Break even point is the point where total revenue equals total cost
R(x) = c(x)
0.21x = 0.124x + 1.1
0.21x - 0.124x = 1.1
0.086x = 1.1
x = 1.1/0.086
x = 12.79 which is approximately 13 units