a) Ta có: \(M=\left\{x\in N|4x\le16\right\}\)
\(\Rightarrow4x\le16\)
\(\Rightarrow x\le4\)
Mà: \(x\in N\Rightarrow x\ge0\)
\(\Rightarrow M=\left\{0;1;2;3;4\right\}\)
b) Ta có: \(N=\left\{x\in N|15< 3x\le33\right\}\)
\(\Rightarrow15< 3x\le33\)
\(\Rightarrow\dfrac{15}{3}< x\le\dfrac{33}{3}\)
\(\Rightarrow5< x\le11\)
\(\Rightarrow N=\left\{6;7;8;9;10;11\right\}\)