First solve the first equation to find x.
x-5=2
x=7
Now plug it in to the other equation to get your answer.
6(7)-20
42-20
22
The answer is 22.
We are given the function below;

PART A
We then proceed to find if the function has a minimum or maximum value. To find if the function has a minimum or maximum value. If the x^2 coefficient is positive, the function has a minimum. If it is negative, the function has a maximum.
ANSWER: From the above, we can see that x^2 is negative, hence the function has a maximum
PART B and C
To find the minimum or maximum value, we would plot the graph of the f(x). The graph can be seen below.
From the graph, the black point helps answer part A and part B.
ANSWER: The function's maximum value is f(x)=2.
This is the point where the slope of the graph is equal to zero
ANSWER: The maximum value then occurs at x= -1
We can also solve this by differentiating the function.
Answer:

Step-by-step explanation:
Use BODMAS rule :
Bracket , Of , Division , Multiplication , Addition , Subtraction
![\sf{2 \times [ 34 - 5 \times (3 + 1) ] }](https://tex.z-dn.net/?f=%20%5Csf%7B2%20%5Ctimes%20%5B%2034%20-%205%20%5Ctimes%20%283%20%2B%201%29%20%5D%20%7D)
Add the numbers : 3 and 1
![\dashrightarrow{ \sf{2 \times [ 34 - 5 \times 4 ] }}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B2%20%5Ctimes%20%5B%2034%20-%205%20%5Ctimes%204%20%5D%20%7D%7D)
Multiply the numbers : 5 and 4
![\dashrightarrow{ \sf{2 \times [ 34 - 20 \: ] }}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B2%20%5Ctimes%20%5B%2034%20%20-%2020%20%5C%3A%20%5D%20%20%7D%7D)
Subtract 20 from 34

Multiply the numbers : 2 and 14

Hope I helped!
Best regards! :D