SOLUTION: Students were asked to write an algebraic expression for the sum of three consecutive natural numbers. One student wrote x + (x + 1) + (x + 2) = 3x + 3. Another wrote (x - 1) + x

Algebra ->  Real-numbers -> SOLUTION: Students were asked to write an algebraic expression for the sum of three consecutive natural numbers. One student wrote x + (x + 1) + (x + 2) = 3x + 3. Another wrote (x - 1) + x       Log On


   

Question 919961: Students were asked to write an algebraic expression for the sum of three consecutive natural numbers. One student wrote
x + (x + 1) + (x + 2) = 3x + 3. Another wrote (x - 1) + x + (x + 1) = 3x. Explain who is correct and why.
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
The only trouble I can find is that the natural numbers start at 1. The second version, if x itself is 1, would have one of the numbers to be summed, x-1 NOT a natural number, because 1-1=0, which is acceptable for WHOLE numbers, but not for NATURAL numbers.

The first version, 3x+3, is acceptable. Each of the three consecutive numbers will be Natural if x is chosen among the Natural numbers.