572.
а) 7 2/13 • 2 = 93/13 • 2/1 = 186/13 = 14 4/13
б) 5 7/16 • 8 = 97/16 • 8/1 =97/2 • 1/1 = 97/2 = 48 1/2 = 48,5
в) 8 3/28 • 5 = 307/28 • 5/1 = 1535/28 = 54 23/28
г) 5/1 • 3 1/5 = 5 • 3,2 = 16
д) 6 3/8 • 2 = 51/8 • 2/1 = 51/4 • 1 = 51/4 = 12 3/4 = 12,75
е) 9 2/9 • 9 = 83/9 • 9/1 = 83
573.
а) (3 3/5 - 2 1/15) • 5 = 2 2/3
1) 3 3/5 - 3 1/15 = 3 9/15 - 3 1/15 = 8/15 2) 8/15 • 5/1 = 8/3 = 2 2/3
б) (1 14/17 - 1 1/34) • 34 = 27
1) 1 14/17 - 1 1/34 = 1 28/34 - 1 1/34 = 27/34
2) 27/34 • 34/1 = 27
в) 3/17 • 5 1/4 + 3 14/17 • 5 1/4 = ( 3/17 + 3 14/17) • 5 1/4 = 4/1 • 21/4 = 21
Больше не могу, сори, время поджимает
Пошаговое объяснение:
1.
5 – 4х = 7 – 5х
5x - 4x = 7 - 5
x = 2
2.
6(2х – 3) + 4 = 10
12x - 18 + 4 = 10
12x - 14 = 10
12x = 10 + 14
12x = 24
x = 24 : 12
x = 2
3.
7х – 4 = 4(2х – 7) + 2х
7x - 4 = 8x - 28 + 2x
7x - 4 = 10x - 28
10x - 7x = 28 - 4
3x = 24
x = 24 : 3
x = 8
4.
2 – 5(4х – 7) = 3(6х + 5)
2 - 20x + 35 = 18x + 15
37 - 20x = 18x + 15
18x + 20x = 37 - 15
38x = 22
x = 22 : 38
x = 11/19
5.
3х – 6(5х + 2) = 4 – 5(3х + 4)
3x - 30x - 12 = 4 - 15x - 20
-27x - 12 = -16 - 15x
27x - 15x = 16 - 12
12x = 4
x = 4 : 12
x = 1/3
6.
–11(x – 2) + 2(3 – 2x) + 15x = 0
-11x + 22 + 6 - 4x + 15x = 0
28 ≠ 0
нет решений
2)18÷6=3
3)16-3=13
4)13+20=33