72-32÷4=64
36-18÷2=27
48-24÷3=40
64-16÷8+8=54
64-16÷(8+8)=63
(64-16)÷8+8=14
9*(13-6)=63
6•(27-20)=42
40÷(30-25)=8.
60-x-20=28
60-x=20+28
60-x=48
x=60-48
x=12
60-12-20=28
Ответ:12 пирожков бабушка отдала соседям
7 5/9 - 2 8/9 = 68/9 - 26/9 = (68 - 26)/9 = 42/9 = 14/3 = 4 2/3
7 - 3/8 =(7 * 8 - 3)/8 = (56 - 3)/8 = 53/8 = 6 5/8
10 - 3 7/15 = 10 - 52/15 =(10 * 15 - 52 )/15 = (150 - 52)/15 = 98/15 = 6 8/15
<span>sin(2п+a)sin(a-п)cos(2п-a)ctg(3п-a)/cos(п-a)cos(а-5п)cos(2п+а)tg(-a-п)=sina*(-sina)*cosa*(-ctga)/(-cosa)*cosa*cosa*(-tga)=1</span>
54/6=9
45/9=5
21-5=16
85/17=5
5*16=80
56/8=7
90/15=6
6*7=42
80+42-122=0