Answer:

Step-by-step explanation:
From the question we are told that:
Function given

Co-ordinates
(x,y)=[1, 4]
Generally the second differentiation of function is mathematically given by

Therefore critical point

Generally the substitutions of co-ordinate into function is mathematically given by
For 1

For 4

For critical point 3

Therefore the maximum value of f(x) = –x2 + 6x over the interval [1, 4] is given by

Answer:
The method of solving "by substitution" works by solving one of the equations (you choose which one) for one of the variables (you choose which one), and then plugging this back into the other equation, "substituting" for the chosen variable and solving for the other. Then you back-solve for the first variable.
Step-by-step explanation:
Answer:
$2.60
Step-by-step explanation:
first you need to see how many time 2.90 goes into 20 it is 6, so then you multiply 2.90 times 6 and get 17.40. Lastly you subtract 17.40 from 20 to get 2.60
Hope this helps