a + 3b = (-2, 3, 1) + 3*(4, -1, 2)a + 3b = (-2, 3, 1) + (12, -3, 6)a + 3b = (-2+12, 3-3, 1+6)a + 3b = (10, 0, 7)
a + 3b = (-2, 3, 1) + 3*(4, -1, 2)
a + 3b = (-2, 3, 1) + (12, -3, 6)
a + 3b = (-2+12, 3-3, 1+6)
a + 3b = (10, 0, 7)