[tex] {3}^{72} + 2 \times {3}^{73} + {3}^{74} [/tex]
[tex] = {3}^{72} (1 + 2 \times 3 + {3}^{2} )[/tex]
[tex] = {3}^{72} (1 + 6 + 9)[/tex]
[tex] = {3}^{72} \times 16[/tex]
[tex] = { ({3}^{36}) }^{2} \times {4}^{2} [/tex]
[tex] = {( {3}^{36} \times 4) }^{2} = > p.p[/tex]