Пошаговое объяснение:
56x - 26x + 168 = 720
30х+168=720
30х=720-168
30х=552
x=92/5 = 18 2/5
27a - 13 + 3a = 167
30a-13=167
30a=167+13
30a=180
a=6
12x + 55 = x
12x-x=-55
11x=-55
x=-5
12 - x = 5x + 8
-x-5x=8-12
-6x=-4
x=2/3
3x + 7 = 3 - x
3x+x=3-7
4x=-4
x=-1
5a + 3 = -15 - a
5a+a=-15-3
6a=-18
a=-3
10x -178 = 5 - 178
10x=5
x=1/2
37x - 8 = 42 + 12x
37x-12x=42+8
25x=50
x=2
-69 - (c -78) = -1
-69-с+78=-1
9-с=-1
-с=-1-9
-с=-10
с=10
-67 - (a - 76) = -2
-67-а+76=-2
9-а=-2
-а=-2-9
-а=-11
а=11
(7x +9) - (11x - 7) = 8
7х+9-11х+7=8
-4х+16=8
-4х=8-16
-4х=-8
х=2
