Give a rule in terms of n for the sum of the first n even positive integers

(if f(x)=4x^2 and g(x)=x+1, find (f o g)(x)

65 8 7 4 5 6 8 4 3 2 1 9 5 6 4 2 1 6 5 1 5 1 3 2 3 5 multiply the third number in the first row by the seventh number in the third row. add this result to the fifth number in the second row. add to this total ten times the fourth number in the third row. subtract the eighth number in the first row from the result.

Will give brainliest what is the value of x? enter your answer in the box.