1 4/5:(3/4*8/21+1)-4/9

Răspuns :

3/4 x 8/21 = 1/1 x 2/7 = 2/7
2/7 + 1/1 = 2/7 + 7/7 = 9/7
1 4/5 : 9/7 = 9/5 : 9/7 = 9/5 x 7/9 = 1/5 x 7/9 = 7/45
7/45 - 4/9 = 7/45 - 20/45 = -13/45