2n + 1 , 2n + 3 , 2n + 5
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( 2n + 5 ) + ( 2n + 3 ) = 5 × ( 2n + 1 ) - 15
4n + 8 = 10n + 5 - 15
4n + 8 = 10n - 10
Add both sides 10
4n + 8 + 10 = 10n - 10 + 10
4n + 18 = 10n
Subtract both sides 4n
4n - 4n + 18 = 10n - 4n
18 = 6n
Divide both sides by 6
18 ÷ 6 = 6n ÷ 6
n = 3
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Thus that three numbers are :
2(3) + 1 , 2(3) + 3 , 2(3) + 5
6 + 1 , 6 + 3 , 6 + 5
7 , 9 , 11
And we're done ....
