№ 1
а) 81/135 = 3/5
б) 135/153 = 15/17
в) 558/2358 = 31/131
№ 2
а) -(2а - 3b) + (7a - b) + 2(4a - b) = - 2a + 3b + 7a - b + 8a - 2b = 13a
б) -4(2х - у + 8) + 3(2х - 5у + 2) = -8х + 4у - 32 + 6х - 15у + 6 = -2х - 11у - 26
№ 3
1 9/26 * (13,3 - 9 5/6) : (- 1/2) + 14 = 4 2/3
1) 13,3 - 9 5/6 = 13 3/10 - 9 5/6 = 13 9/30 - 9 25/30 = 12 39/30 - 9 25/30 = 3 14/30 = 3 7/15
2) 1 9/26 * 3 7/15 = 35/26 * 52/15 = 7/1 * 2/3 = 14/3
3) 14/3 : (- 1/2) = 14/3 * (- 2/1) = - 28/3 = - 9 1/3
4) - 9 1/3 + 14 = 14 - 9 1/3 = 13 3/3 - 9 1/3 = 4 2/3