Answer: 9.70%
Step-by-step explanation:
The formula to find the percentage error is given by :-

Given : Actual mass of zinc oxide used by pharmacist = 28.35 g
Estimated mass of zinc oxide used by pharmacist =31.1 g
Now, 
i.e. 
i.e. 
Hence, the percentage of error on the basis of the desired quantity.= 9.70%
Answer:

Step-by-step explanation:
First of all, the number before the decimal would be the whole number of the fraction.
So, 
Then, you would put 0.83 over a fraction.
So because you cannot simplify it anymore, it would be 
Answer: (a) e ^ -3x (b)e^-3x
Step-by-step explanation:
I suggest the equation is:
d/dx[integral (e^-3t) dt
First we integrate e^-3tdt
Integral(e ^ -3t dt) as shown in attachment and then we differentiate the result as shown in the attachment.
(b) to differentiate the integral let x = t, and substitute into the expression.
Therefore dx = dt
Hence, d/dx[integral (e ^-3x dx)] = e^-3x
Answer: -2.1p + 1.7
2.4 - 6p - 0.7 + 3.9p
Subtract 6p from 3.9p. (-2.1p)
Subtract 0.7 from 2.4. (1.7)