Question

Find three consecutive integers whose sum is 558

Answer 1

Those are 185, 186 and 187

What you do is create this system of equations:

x+y+z=558  (three integers add up to 558)
x+1=y  (they are consecutive, so that is translated as a number+1)
y+1=z (same logic as before)

And then you just resolve that system.