12x-x-55=0

11x - 55 = 0

11x = 55

x = 55 : 11

x = 5

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12 * 5 - 5 -55 = 0

      60 - 5 - 55 = 0

            55-55=0

2+6a+4a=92

 2 + 10a = 92

10a = 92 -2

10a = 90

a = 90 : 10

a = 9

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2 + 6*9 + 4*9 = 92

   2 + 54 + 36 = 92

    2 + 90 = 92

           92 = 92

Verified answer

12х-х-55=0

12х-х=55

х=55:11

х=5

12*5-5-55=0

0=0

2+6а+4а=92

6а+4а=92-2

10а=90

а=90:10

а=9

2+6*9+4*9=92

92=92