2/3 - 11/6 = (2×2)/(3×2) - 11/6 = 4/6 - 11/6 = -7/6
-5/18 + 4/9 = -5/18 + (4×2)/(9×2) = -5/18 + 8/18 = 3/18 = (3×1)/(3×6) = 1/6
3/12 ÷ 5/6 = 3/12 × 6/5 = (3×6)/(12×5) = (3×3×2)/(3×2×2×5) = 3/(2×5) = 3/10
-1/6 + 2/3 - 7/18 = (-1×3)/(6×3) + (2×6)/(3×6) - 7/18
= -3/18 + 12/18 - 7/18
= 2/18
= (2×1)/(2×9)
= 1/9
ad/6 ÷ 6d/18a = ad/6 × 18a/6d
= 18a²d/36d
= (18a²d)/(2×18d)
= a²/2
24/(-9) ÷ 8 = (3×8)/(-3×3) × 1/8 = 8/(-3) × 1/8 = -1/3
