Answer:
x = 72
Step-by-step explanation:
2/3x + 6 = 1/2x + 1/4x
2/3x + 6 = 3/4x
3/4 - 2/3 = 1/12
6 = 1/12x
Multiply 6 by 12 to get x
x = 72
The exponential function is given in the form

where a is the initial value and b is the multiplicative rate of change
So lets plug the first two values of the table in this function , we get
or

Now plug second

Divide equation 2 by equation 1

On simplifying we get

or

So the multiplicative rate of change of the function is

Brand A costs $2 per ounce, B is $1, C is $0.50(?) I think
Answer:
I'm pretty sure it's both, but I can see this is a summative exam/test so I'm really sorry if it's wrong.
Answer: 12$
Step-by-step explanation:
We need to round 79.45 to the nearest 10 dollars, which is 80.
We can then get 15% of it easily since its a whole number by adding 10% (8) and 5% (4) to get an estimate of around 12 dollars.