The sum of three consecutive odd integers is 57. What are the three numbers?
A. 17, 19, 21
B. 15, 19, 23
C. 19, 21, 23
D. 18, 19, 20

Question

The sum of three consecutive odd integers is 57. What are the three numbers?
	A.	17, 19, 21
	B.	15, 19, 23
	C.	19, 21, 23
	D.	18, 19, 20

zepdrix · Answer

Let the first unknown integer be $x$.
Since our numbers are CONSECUTIVE, the next odd will be $x+2$.
Does that make sense?

Imagine the first number was $5$.
The next number would be $7$ or another way to think about it, $5+2$.

Then the third consecutive off integer will be $x+4$.

zepdrix · Answer

The sum of these three values is 57.
So the first number, $x$ plus the second number $x+2$ plus the third number $x+4$ totals 57.

$x+(x+2)+(x+4)=57$

And from here we can solve for $x$ doing some algebra!
You can drop the brackets since nothing is being applied to them on the outside. I was just doing that for clarity.