Помогите решить:
а)1/4x4 3/4x16/57+(4 3/4+1 2/3)x16/21+2/27x4 1/2
б)(4/5+1/6)x(23 2/3-15 5/9)x45/58-1/2

1) =1/4*19/4*16/57 + (19/4+5/3)*16/21 + 2/27*9/2 = 1/3+77/12*16/21+1/3=1/3+44/9+1/3=2/3+44/9=50/9=5 5/92) = 29/30*73/9*45/58-1/2=7312-1/2=67/12=5 7/12