A number is a mathematical object used to count, measure, and label
Answer:
Bag 2
Step-by-step explanation:
Given
Bag 1:

Bag 2:

Required
Which is a better buy
To get which buy is better, we first get the unit price of each bag.

For bag 1:


For bag 2:


The best buy is the one with smaller unit price
Hence, bag 2 is better to buy
Lets get started :)
f(x) =

- 2
y =

- 2
This is the original equation, and now we have to find the inverse.
When finding the inverse, just flip the variables, x as y and y as x
f ⁻¹(x)
↓
x =

- 2
We have to isolate y as it is our f ⁻¹(x)
Take 2 to the other side { When you see subtraction, you do addition }
x + 2 =

Take 9 to the other side { When you see division, you do multiplication }
9 ( x + 2 ) = y
9x + 18 = y
f ⁻¹ (x) = 9x + 18
If it is to match 3+1 which is 4 the value to satisfy X is -1
128+7=135
135=100%
10%=13.5
1%=1.35
13.5-(3×1.35)=9.45
I believe that 9.45% is the answer