1)
(3/4 + 1/5) * 5/19 = 1/4,
1) 3/4 + 1/5 = 15/20 + 4/20 = 19/20,
2) 19/20 * 5/19 = 5/20 = 1/4,
2)
(12 1/3 - 7 3/4) * 6/11 = 2 1/2,
1) 12 1/3 - 7 3/4 = 12 4/12 - 7 9/12 = 11 16/12 - 7 9/12 = 4 7/12,
2) 4 7/12 * 6/11 = 55/12 * 6/11 = 5/2 = 2 1/2,
3)
(2 3/5 - 5/8) : 19 3/4 = 1/10,
1) 2 3/5 - 5/8 = 2 24/40 - 25/40 = 1 64/40 - 25/40 = 1 39/40,
2) 1 39/40 : 19 3/4 = 79/40 : 79/4 = 79/40 * 4/79 = 4/40 = 1/10