Решите 20 б только правильно 1) 2,1/6+2,5/12 1)2,7/9-1/3 2) 9,3/8+7,5/6 2)3,4/5-2/3

1) 2,1/6+2,5/12 = 21/10 : 6 + 25/10 : 12 = 21/10 * 1/6 + 25/10 * 1/12 = 7/10 * 1/2 = 7/20
1)2,7/9-1/3 = 27/10 : 9 - 1/3 = 27/10 * 1/9 - 1/3 = 3/10 - 1/3 = 9/30 - 10/30 = - 1/30
2) 9,3/8+7,5/6 = 93/10 : 8 + 75/10 : 6 = 93/10 * 1/8 + 75/10 * 1/6 = 93/80 + 75/60 = 279/240 + 300/240 = 579/240 = 2,4125
 2)3,4/5-2/3 = 34/10 : 5 - 2/3 = 34/10 * 1/5 - 2/3 = 34/50 - 2/3 = 102/150 - 100/150 = 2/150 = 1/75