Как решить пример (2 8/9) • (1/7+8/49)

2 целых 8/9 * (1/7 + 8/49) =

= [ (2*9+8) / 9 ] * ([ (1*7) / (7*7) ] + 8/49) =

= 26/9 * (7/49 + 8/49) =

= 26/9 * [ (7+8) / 49 ] =

= 26/9 * 15/49 =

= (26 * 15) / (9*49) =

= (26 * 5) / (3*49) =

= 130/147

по действиям:

1) 1/7 + 8/49 = 7/49 + 8/49 = 15/49

2) 2 8/9 * 15/49 = 26/9 * 15/49 = (26 * 15) / (9*49) =

= (26 * 5 * 3) / (3*3*49) = (26*5) / (49*3) = 130/147