3 1/8 ÷ 15/16 - 1/4
1) 3 1/8 = 25/8
25/8÷15/16=25/8×16/15 = 25×16/8×15= 400/120 =40/12 = 10/3
2) 10/3 - 1/4 = 10×4-1×3/12= 40-3/12=37/12 = 3 1/12
1 9/35 ÷ (1 1/5 + 2/3)
1) 1 1/5+2/3 = 6/5+2/3 = 6×3+2×5/15= 18+10/15=28/15 или 1 13/15
2) 1 9/35 ÷ 1 13/15 = 44/35 ÷ 28/15 = 44/35 × 15/28 = 44×15/35×28 = 660/875 = 132/175