Let n be the unknown value
n + (n+2) + (n+4) = 408
Then we would simplify by combining like terms
n + n + 2 + n + 4 = 408
3n+6=408
-6 -6
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3n=402
Divide.
3n=402
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3 3
n = 134.
So the first integer is 134. Then plug in the rest to the n+2 and n+4
134+2= 136
134+4= 138
The integers are then 134, 136, 138
