Factor the Sum of Two Cubes: a³ + b³

a³ + b³ = (a + b)(a² - ab + b²)

The sign of +b³ is plus.
Then the sign in (a + b) is plus.
And the sign of -ab is minus.

Change x³ + 8 to the sum of two cubes.

x³ is x³.
+8 is +2³.

x³ + 2³ is the sum of two cubes.
So x³ + 2³ = (x + 2)(x² - x⋅2 + 2²).

+2³ is plus.
So the sign in (x + 2) is plus.
And the sign of -x⋅2 is minus.

-x⋅2 = -2x
+2² = +4

So (x + 2)(x² - 2x + 4) is the answer.