For this case we have the following expression:

Rewriting the expression we have:
1) First we subtract the numbers within the parenthesis:

2) Then, we solve the exponents:

3) Then, multiplication:

4) Finally, the addition of numbers is made:

Answer:
the value of the expression is:
B: 29
Step-by-step explanation:
mean = sum of observation/ no. of observation
mean = 3+5+6+4+7+3+9+8/ 8
<h2>mean = 45/8 = 5.6</h2>
1. n=18
2. n=18
3. x=4
4. a= -12
5. x=3