Given ∑n=1∞an=5\sum_{n=1}^{\infty} a_n = 5∑n=1∞an=5 and ∑n=1∞bn=2\sum_{n=1}^{\infty} b_n = 2∑n=1∞bn=2, find ∑n=1∞(3an−bn)\sum_{n=1}^{\infty} (3a_n - b_n)∑n=1∞(3an−bn).
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