l 2x + 6 l + 1 kurang dari 3

( 2x + 6) + 1 < 3      atau     (2x + 6) < -3 - 1
(2x + 6) < 3-1                      2x < -6 -4
(2x+6) < 2                           2x < -10
2x < -6 + 2                           x < -10/2
2x < -4                                 x < -5
x < -4/2
x < -2