덧셈과 뺄셈 문제풀이 1) (-7) + (+12) - (-8) = +(12-7) +(+8) = 5+8 = 13 2) (+4/3) - (-1/5) + (+6/5) + (-2/3) = +(4/3 – 2/3) + (+1/5)+(6/5) = 2/3 + 7/5 = 10/15 + 21 / 15 = 31/15 3) (-5) + (+7) - (-3) - (+4) = +(7-5) + (+3) + (-4) = (+2) + (+3) + (-4) = (5-4) = 1 4) (+3/4) + (-1/3) - (-1) = (+9/12) + (-4/12) + (12/12) = (9-4+12)/12 = 17/12  1) 5 + 16 – 14 = 21-14 = 7 2) -15 + 2 + 13 – 8 = -15 + (2+13) – 8 =..