If $A=\left\{3^{2 n}-1: n \in N\right\}$ and $B=\{8 n: n \in N\}$ then

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Professor PC Thomas Classes · Answer

$3^{2n}-1 = 9^n-1 = (1+8)^n-1 = 8k$. Thus, every element of $A$ is a multiple of 8, so $A \subset B$.