✔ 最佳答案
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記住正正得正、正負得負、負正得負、負負得正。
(-6)除(+6)
= -(6÷6) <-- 負正得負
= -1
(-5)除(-15)
= +(5÷15) <-- 負負得正
= 3 分之 1
(+13)除(-39)
= -(13÷39) <-- 正負得負
= 3 分之 1
(-5)-(-2/5)
= -5 + 2/5 <-- 負負得正
= 2/5 - 25/5
= -23/5
(-16)x(-3/4)
= 16 × 3/4 <-- 負負得正
= 4 × 3
= 12
(-1/6)x(-3/2)
= 1/6 × 3/2 <-- 負負得正
= 1/2 × 1/2
= 1/4
(-40)除(-4/7)
= 40 ÷ (4/7) <-- 負負得正
= 40 × 7/4
= 70
(-5/8)除(+8又3/4)
= -[(5/8)÷(+8又3/4)] <-- 負正得負
= - {(5/8) ÷ [(8×4+3)/4]}
= - [(5/8) ÷ (35/4)]
= - [(5/8) × (4/35)]
= - ( 1/2 × 1/7 )
= -1/14