Question

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

Answer 1

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