Question 20261
the sum of three consecutice numbers is 417. 
You need 3 CONSECUTIVE numbers, 3 numbers that are one right after the other.
If you use x, y & z you are using 3 numbers that are not necessarily consecutive. 
So we will begin by letting x be the first number, the next number will be the number right after x, so it will be x+1, and our third number will be two numbers after x, so it will be; x+2
so we have:
x+(x+1)+(x+2)=417
Now we can solve for x to get our first number.
Add al like terms first in the equation;
3x+3=417
Now subtract 3 from both sides;
3x+3-3=417-3
3x=414
Divide both sides by 3;
{{{3x/3}}}={{{414/3}}}
x=138
So now we have our first number;
So the second number would be;
x+1=138+1=139
So we have; 138,139
Now our third number would be;
x+2=138+2=140
So your three consecutive numbers are:
138, 139,140
Hope you understand
=)