(9 4/15 - 5 3/5 · 1 1/7) · 2 1/43 = 5 4/5.
1) 5 3/5 · 1 1/7 = 28/5 · 8/7 = (4·8)/(5·1) = 32/5 = 6 2/5
2) 9 4/15 - 6 2/5 = 8 19/15 - 6 6/15 = 2 13/15
3) 2 13/15 · 2 1/43 = 43/15 · 87/43 = 87/15 = 29/5 = 5 4/5
Ответ: 5 целых 4/5.
2х - 3у = 4
3х + 3у = 11
2х - 3у = 4
(3 + 1 * 2)х + (3 + 1 * (-3))у = 11 + 1 * 4
2х - 3у = 4
5х = 15
2х - 3у = 4
х = 15
у = 2/3
х = 3
1) 75 × (2×5) = 750
750 × (2×5) = 7500
7500 × (2×5) = 75000
2) 720 : (9×4) = 20
3600 : (9×4) = 100
72 : (9×4) = 2
3) (20×8) × (28×4) = 17 920
Решение предоставлено на листочке...