Plz help me well mark brainliest if correct.

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C) The mean is about 100.

Step-by-step explanation:

We see that the best fit line (out of the options listed) would be y=100. The mean can also be algebraically calculated with the following equation:

Let be the mean (average) of the values:

, which is closest to answer choice C) The mean is about 100.

a4 - 3a2 - 1

step-by-step explanation:

step   1   :

equation at the end of step   1   :

  ((a4) -   3a2) -   1

step   2   :

trying to factor by splitting the middle term

2.1     factoring   a4-3a2-1  

the first term is,   a4   its coefficient is   1 .

the middle term is,   -3a2   its coefficient is   -3 .

the last term, "the constant", is   -1