2 1/2*48-3 2/3:1/18+5 5/12:7/36=

2 1/2• 48 - 3 2/3: 1/18 + 5 5/12: 7/36 = 81 6/7

1)) 2 1/2• 48 = (2•2+1) / 2 • 48/1 = 5/2• 48/1 = 5/1• 24/1 = 5•24 = 120

{2 и 48 сократили значит поделили на 2}

2)) 3 2/3 : 1/18 = (3•3+2) / 3• 18/1 = 11/3• 18/1 = 11/1• 6/1 = 11• 6 = 66

{сократили 3 и 18 на 3}

3)) 5 5/12 : 7/36 = (12•5+5) / 12 • 36/7 = 65/12• 36/7 = 65/1• 3/7 = 195/7 = 27 6/7

{сократили 12 и 36 на 12}

4)) 120 - 66 + 27 6/7 = 54 + 27 6/7 = 81 6/7