Answer:
the g's contributing term for the overall uncertainty of P is ![dP_g = [\frac{dg}{g}]](https://tex.z-dn.net/?f=dP_g%20%3D%20%20%5B%5Cfrac%7Bdg%7D%7Bg%7D%5D)
Step-by-step explanation:
From the question we are told that
The pressure is 
The first step in determining the uncertainty of P in by obtaining the terms in the equation contributing to it uncertainty and to do that we take the Ln of both sides of the equation

=>
Then the next step is to differentiate both sides of the equation

=> 
We asked to obtain the contribution of the term g to the uncertainty of P
This can deduced from the above equation as
![dP_g = [\frac{dg}{g}] P](https://tex.z-dn.net/?f=dP_g%20%3D%20%20%5B%5Cfrac%7Bdg%7D%7Bg%7D%5D%20P)
No, 1/a^b (a^-b) doesn't equal -a^b
Step-by-step explanation:
Tax charge
80 × 6.75/100 = 5.4
Cost + tax charge
80 + 5.4 = 85.4
Tip (15% of cost and tax)
85.4 × 15/100 = 12.81
(Cost + tax charge + tip)
85.40 + 12.81 = 98.21
therefore, $95 is not enough.