Find the three numbers in a row where two times the first number increased by six times the third number is the same as three times the second number plus 89

we call : a, b, c - the numbers in a row a

b = a + 1

c = a + 2

2a + 6c = 3b + 89

2a + 6 (a+2) = 3 (a+1) + 89

2a + 6a + 12 = 3a + 3 + 89

8a + 12 = 3a + 92

8a - 3a = 92 - 12

5a = 80

a = 80 : 5 b = a+1 ⇒ b = 16 + 1 ⇒ b = 17

a = 16 c = a+2 ⇒ c = 16 + 2 ⇒ c = 18