Expanding the terms, we have:
(3x - 1)(3x + 1) = 9x^2 + 3x - 3x - 1 = 9x^2 - 1
(3x + 1)^2 = (3x + 1)(3x + 1) = 9x^2 + 3x + 3x + 1 = 9x^2 + 6x + 1
Now, adding both expressions together:
(3x - 1)(3x + 1) + (3x + 1)^2 = (9x^2 - 1) + (9x^2 + 6x + 1)= 9x^2 - 1 + 9x^2 + 6x + 1= 18x^2 + 6x
Therefore, the final expression is 18x^2 + 6x.
Expanding the terms, we have:
(3x - 1)(3x + 1) = 9x^2 + 3x - 3x - 1 = 9x^2 - 1
(3x + 1)^2 = (3x + 1)(3x + 1) = 9x^2 + 3x + 3x + 1 = 9x^2 + 6x + 1
Now, adding both expressions together:
(3x - 1)(3x + 1) + (3x + 1)^2 = (9x^2 - 1) + (9x^2 + 6x + 1)
= 9x^2 - 1 + 9x^2 + 6x + 1
= 18x^2 + 6x
Therefore, the final expression is 18x^2 + 6x.