6x=-12 30x=-6 2x+7=0 7x-2=9 13-2x=8x 6x-5=2+3x ! с проверкой

-6x=-12,
х=-12:(-6),
х = 2,

-6*2=-12,
-12=-12,

30x=-6,
х=-6:30,
х = -1/5,

30*(-1/5)=-6,
-30/5=-6,
-6=-6,

2x+7=0,
2х=-7,
х=-7:2,
х = -3,5,

-2*3,5+7=0,
-7+7=0,
0=0,

7x-2=9,
7х=9+2,
7х=11,
х=11:7,
х = 11/7,
х = 1 4/7,

1 4/7*7-2=9,
11/7*7-2=9,
11-2=9,
9=9,

13-2x=8x,
-2х-8х=-13,
-10х=-13,
х=13:10,
х = 13/10,
х = 1 3/10,

13 - 2*1 3/10=8* 1 3/10,
13 - 26/10=104/10,
104/10=104/10,

6x-5=2+3x,
6х-3х=2+5,
3х=7,
х=7:3,
х=7/3,
х = 2 1/3,

6 * 2 1/3 - 5=2 + 3* 2 1/3,
42/3 - 5= 2+21/3,
27/3=27/3