Question

The sum of three consecutive integers is 1,623

Answer 1

Set the unknown integer to x. Since they are consecutive integers the next will be x+1 and the next x+2. So

x + x+1 + x+2 = 1623
3x + 3 = 1623
3x = 1620
x = 540

x+1 = 541
x+2 = 542

The consecutive integers are 540, 541, and 542.

Answer 2

Well to solve this you write out three equations 
x+(x+1)+(x+2)=1623

then

3x=1620
x=540

so the three consecutive integers are 540,541, and 542.