Пошаговое объяснение:
1)
-6(х+2)=4х-17
-6x - 12 = 4x - 17
4x + 6x = -12 + 17
10x = 5
x = 5 : 10
x = 0,5
2)
(18х-19)-(4-7х)=-73
18x - 19 - 4 + 7x = -73
25x - 23 = -73
25x = -73 + 23
25x = -50
x = -50 : 25
x = 2
3)
10х+3(7-2х)=13+2х
10x + 21 - 6x = 13 + 2x
4x + 21 = 13 + 2x
4x - 2x = 13 - 21
2x = -8
x = -8 : 2
x = -4
4)
9(х-1)=х+15
9x - 9 = x + 15
9x - x = 15 + 9
8x = 24
x = 24 : 8
x = 3
5)
(11х+14)-(5х-8)=25
11x + 14 - 5x + 8 = 25
6x + 22 = 25
6x = 25 - 22
6x = 3
x = 3 : 6
x = 0,5
6)
12-4(х-3)=39-9х
12 - 4x + 12 = 39 - 9x
24 - 4x = 39 - 9x
9x - 4x = 39 - 24
5x = 15
x = 15 : 5
x = 3
7)
2(3х+5)-3(4х-1)=11,8
6x + 10 - 12x + 3 = 11,8
-6x + 13 = 11,8
6x = 13 - 11,8
6x = 1,2
x = 1,2 : 6
x = 0,2
1)
∠MON=90°
∠MOK+∠KON=∠MON
∠MOK+∠KON=90°
(3x-26°) + (x-12°) = 90°
4x - 38° = 90°
4x = 90°+ 38°
x = 128° : 4
x = 32°
∠MOK = 3x - 26° = 3 · 32° - 26° = 70°
∠KON = x - 12° = 32° - 12° = 20°
ответ: 70°; 20°
2)
∠MON=90°
∠MOK+∠KON=∠MON
∠MOK+∠KON=90°
(3x+20°) + (2x+15°) = 90°
5x +35° = 90°
5x = 90°- 35°
x = 55° : 5
x = 11°
∠MOK = 3x +20° = 3 · 11° + 20° = 53°
∠KON = 2x + 15° = 2·11° + 15° = 37°
ответ: 53°; 37°
3)
∠MON=90°
∠MOK+∠KON=∠MON
∠MOK+∠KON=90°
(4x-10°) + x = 90°
5x - 10° = 90°
5x = 90°+ 10°
x = 100° : 5
x = 20°
∠MOK = 4x - 10° = 4 · 20° - 10° = 70°
∠KON = x =°
ответ: 70°; 20°
2)50:5=10(кг)
ответ: в одном бидоне было 10 кг сметаны
Надеюсь всё понятно :)