№5
Вопрос
Номер 9.
Решите уравнение.
а) x + 5/13 = 7/13 x = 7/13 – 5/13 x = 2/13 б) y – 18/23 = 5/23 y = 18/23 + 5/23 y = 23/23 = 1 в) 14/19 – x= 8/19 x = 14/19 – 8/19 x = 6/19 г) х/15 = 5 x ∶ 15 = 5 x = 5 · 15 x = 75 д) 120/у = 30 120 ∶ y = 30 y = 120 ∶ 30 y = 4 е) 320/8+х = 4 320 : (8 + x ) = 4 8 + x = 320 ∶ 4 8 + x = 80 x = 80 – 8 x = 72
а) x + 5/13 = 7/13
5/13
7/13
x = 7/13 – 5/13
7/13
5/13
x = 2/13
2/13
б) y – 18/23 = 5/23
18/23
5/23
y = 18/23 + 5/23 y = 23/23 = 1 в) 14/19 – x= 8/19 x = 14/19 – 8/19 x = 6/19 г) х/15 = 5 x ∶ 15 = 5 x = 5 · 15 x = 75 д) 120/у = 30 120 ∶ y = 30 y = 120 ∶ 30 y = 4 е) 320/8+х = 4 320 : (8 + x ) = 4 8 + x = 320 ∶ 4 8 + x = 80 x = 80 – 8 x = 72
18/23
5/23
y = 23/23 = 1
23/23
в) 14/19 – x= 8/19
14/19
8/19
x = 14/19 – 8/19
14/19
8/19
x = 6/19
6/19
г) х/15 = 5
х/15
x ∶ 15 = 5
x = 5 · 15
x = 75
д) 120/у = 30
120/у
120 ∶ y = 30
y = 120 ∶ 30
y = 4
е) 320/8+х = 4
320/8+х
320 : (8 + x ) = 4
8 + x = 320 ∶ 4
8 + x = 80
x = 80 – 8
x = 72
Вопрос
Номер 10.
Представьте в виде смешанного числа дробь.
а) 76/5 ; 76 : 5 = 15 (ост. 1), поэтому 76/5 = 15 1/5 ; б) 83/16 ; 83 : 16 = 5 (ост. 3), поэтому 83/16 = 5 3/16 .
76/5
1/5
83/16
3/16
Вопрос
Номер 11.
Представьте смешанное число в виде неправильной дроби.
а) 5 6/7 = 7 · 5 + 6/7 = 41/7 ; б) 8 5/9 = 9 · 8 + 5/9 = 77/9 .
6/7
7 · 5 + 6/7
41/7
5/9
9 · 8 + 5/9
77/9
Вопрос
Номер 12.
Выполните действия.
а) 1 9/11 + 2 3/11 = (1 + 2)+( 9/11 + 2 3/11 )= 3 + 12/11 = 3 + 1 1/11 = 4 1/11 ; б) 3 2/9 + 1 7/9 = (3 + 1)+( 2/9 + 7/9 )= 4 + 9/9 = 4 + 1 = 5; в) 4 1/3 – 2 2/3 = 13/3 – 8/3 = 13 – 8/3 = 5/3 = 1 2/3 ; г) 26 2/5 – 17 3/5 = 25 5 + 2/5 – 17 3/5 = (25 – 17) + ( 7/5 – 3/5 ) = 8 4/5 ; д) 8 2/7 – 3 4/7 = 7 7 + 2/7 – 3 4/7 = (7 – 3) + ( 9/7 – 4/7 ) = 4 5/7 .
9/11
3/11
9/11
3/11
12/11
1/11
2/9
7/9
2/9
7/9
9/9
1/3
2/3
13/3
8/3
13 – 8/3
5/3
2/3
2/5
3/5
5 + 2/5
3/5
7/5
3/5
4/5
2/7
4/7
7 + 2/7
4/7
9/7
4/7
5/7
