If we call the first integer n, the next three integers must be one multiple of 2 away each, giving us the integers n, n + 2, n + 4, and n + 6. We’re told these sum to -28, so we can put these integers into the equation
n + (n + 2) + (n + 4) + (n + 6) = -28
Solving for n:
n + n + 2 + n + 4 + n + 6 = 28
4n + 12 = -28 (collecting like terms)
n + 3 = -7 (diving both sides by 4)
n = - 10
So our four integers are -10, -8, -6, and -4.