8/15 + 1/5 + (2/3)2 = 8/15 + 3/5 + 4/9 = 24/45 + 27/45 + 20/45 = 71/ 45 =
= 1 26/45
1)13613-8999=4614
2) 7373-1880=6493
3) 90×3=270
4) 9557-4614=85943
5) 85943+6493=93436
6) 92436+270=92706-ответ
720-80=640м. S= 720*640=460800м2= 46,08 га.
-1/15*15/8 + 25/6 : 5/3 = - 1/8 + 5/2 = -1/8 + 20/8 = 19/8 = 2 3/8