SOLUTION: If z is a whole number, explain why the value of the expression z(z+1) is always even

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Question 862313: If z is a whole number, explain why the value of the expression z(z+1) is always even
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
If +z+ is odd, then
+z+%2B+1+ is even, and
+z%2A%28+z+%2B+1+%29+ is odd x even
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If +z+ is even, then
+z+%2B+1+ is odd, and
+z%2A%28+z+%2B+1+%29+ is even x odd
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In both cases, you have an even
number with an odd multiplier
which has to be even