Let's call a, b, c and d he four consecutive integers.
Then, twice the 3rd number decreased by the second number is 8, so:
2c - b = 8
They are consecutive so:
b = a + 1
c = a + 2
d = a + 3
Replacing on the first equation and solving for a, we get:
2c - b = 8
2(a+ 2) - (a + 1) = 8
2a + 4 - a - 1 = 8
a + 3 =