Inductive Proof (+linear equation in four variables)

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sweetreason
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I'm trying to prove by induction that [tex]\forall n \geq 5, \exists m_1, m_2 \in \mathbb{N}[/tex] such that [tex]n = 2m_1 +3m_2.[/tex]I've done the base case, and the inductive step boils down to showing that [tex]\exists m_1 \prime m_2 \prime[/tex] such that [tex]2m_1 +3m_2 +1 = 2m_1 \prime +3m_2 \prime[/tex]. Maybe I'm forgetting something from grade school algebra, but I have no idea how to solve for [tex]m_1 \prime, m_2 \prime[/tex]. I've plugged it into wolfram alpha [http://www.wolframalpha.com/input/?i=2*x_1+3*x_2+++1+=+2*y_1+++3*y_2] and got solutions (all I care about is the case n =1 for the integer solutions wolfram gives) but I want to know how to arrive there.
 
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