Identify the linear term in the function

  -5x

Step-by-step explanation:

The linear term is the term with the variable to the first power. Here, it is -5x.

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Comment on other terms

2x^2 has x to the 2nd power

-12 has x to the 0 power (no variable)

The mean is the average of the numbers. It is easy to calculate: add up all the numbers, then divide by how many numbers there are. In other words it is the sum divided by the count.