Answer:
n = 4
Step-by-step explanation:
Put the given values in the equation and solve for n.
9 = 4n -7
16 = 4n . . . . . . add 7
4 = n . . . . . . . . divide by 4
The value of n is 4 so that m(4) = 9.
The length of the line segment AB where

and


We have:

subtitute

Answer: b. 14.1
Not sure is this is right but if the chemist wants to make the solution 35% acidic then he can use all of the 30% acid and 5% of the 45% acid.