Сравните дробь 12\17 и 17\12

1)4:4=1(ш)
S=4*1
S=4
P=4+4+1+1
P=10

1) 












3)

x = 6 - y
5*(6 - y) - 2y = 9
30 - 5y - 2y = 9
-7y = -21
y = 3
x = 6 - 3 = 3

4)

x = 6y - 2
2*(6y - 2) + 3y = 11
12y - 4 + 3y = 11
15y = 15
y = 1
x = 6*1-2 = 4

5)

x = 5y + 4
4*(5y+4) - 3y = -1
20y + 16 - 3y = -1
17y = -17
y = -1
x = 5 * (-1) + 4 = -1

2)

21:3=7 новых парт вы классе

6x+2x=4,2-2,352
8x=1,848
x=1,848:8
x=0,231