решить пример с решением 7 * 2 6/7 + 53/12:(7/9:9/4)

7*2*6/7+53/12 / (7/9-9/4)= 12 + 53/12 / (-53/36) = 12 + (-53/12 * 36/53) = 12 + (-3) = 9

1) 7/9 : 9/4 = 7/9 * 4/9 = 28/81,

2) 53/12 : 28/81 = 53/12 * 81/28 = 1431/112 = 12 87/112,

3) 7 * 2 6/7 = 7 * 20/7 = 20,

4) 20 + 12 87/112 = 32 87/112