Question

add X square + X + 1 and x square minus x + 1 subtract minus x square minus x + 1

Answer 1

(x ^2 + x + 1) + ( x^2 - x +1) = 2x^2 +2
and
(2x^2 +2 ) - ( - x^2 - x +1)
= 2x^2 +2 + x ^2 +x -1
= 3x^2 +x +1