Помогите решить:

(4/5+1/6) • (23 2/3-15 5/9) •45/58-1/2

1) 4/5+1/6 = (4*6+1*5) / 30 = (24+5) / 30=29/30

2) 23 2/3-15 5/9 = (23*3+2) / 3 - (15*9+5) / 9=71/3-140/9 = (71*3-140) / 9 = (213-140) / 9=73/9

3) 29/30*73/9=2117/270

4) 2117/270*45/58 = (2117*45) / (270*58) = (73*1) / (6*2) = 73/12

5) 73/12-1/2 = (73-1*6) / 12=67/12=5 7/12