7:(5/8+5/6) + (3 1/9 - 1/3) ×(3/10)²=
= 7: ( 30/48+ 40/48) + ( 28/9 - 3/9 ) × 9/100=
= 7/1 × 48/70 + 25/9 × 9/100=
=48/10 + 25/100 =4,8+0,25= 5,05
по действиям:
1) 5/8 + 5/6 = 30/48 + 40/48= 70/48 = 35/24= 1 11/24
2) 3 1/9 - 1/3 = 28/9 - 3/9 =25/9 = 2 7/9
3) 7 : 1 11/24 = 7/1 * 24/35 = 24/5 = 4,8
4) 2 7/9 × (3/10) ²= 25/9 × 9/100= 25/100=0,25
5) 4,8 + 0,25= 5,05