Answer: One tail test.
Step-by-step explanation:
Given : A sample of 36 observations is selected from a normal population. The sample mean is 12, and the population standard deviation is 3.
Also, The set of hypothesis to conduct a test :-

The kind of test need to perform is dependent upon the alternative hypothesis.
Since, the alternative hypothesis is one tailed (right-tailed), so the test is one tail test.
No this isn’t a function because it doesn’t pass the vertical line test.
Answer:
- 11x - 2
Step-by-step explanation:
note that (f + g)(x) = f(x) + g(x)
f(x) + g(x)
= 2x + 1 - 13x - 3 ← collect like terms
= - 11x - 2