Weather Temperature Expectation

Question

In the below question, I found the answers of the sub-questions as follows,

a) (-3*(1/8))+(6*(1/2))+(9*(3/8)) = 6

b) 6^2 = 36

c) (3*6+1)^2 = 19^2 = 361

But they turned out to be wrong, I appreciate the help in advance!

Tomorrow's weather temperature is modelled as a discrete random variable X and the forecasts reflect
that three values can be considered with certain​ probabilties, as given in the PMF table below. Let 
be a random variable with the probability distribution below.

m      -3    6     9
Px(m) 1/8   1/2   3/8

a) The expected temperature for tomorrow will be E(X)?

b) You want to model another random event as a function of X such that Y = X^2. ​Then, E(Y)? 

c) You through that your approach in part b was​ wrong, and Y should be (3X+1)^2 instead of just X^2. 
Then, E(Y)?

Answer 1

b)

$$E(X^2)=(-3)^2\times\frac{1}{8}+6^2\times\frac{1}{2}+9^2\times\frac{3}{8}$$

You calculated $E^2(X)$ instead

c) similarly