[tex]3) {10}^{2} - {( {7}^{3} \times {7}^{3}) }^{3} \div {49}^{8} [/tex]
[tex] = 100 - {( {7}^{3 + 3}) }^{3} \div { ({7}^{2}) }^{8} [/tex]
[tex] = 100 - { {(7}^{6}) }^{3} \div {7}^{2 \times 8} [/tex]
[tex] = 100 - {7}^{6 \times 3} \div {7}^{16} [/tex]
[tex] = 100 - {7}^{18} \div {7}^{16} [/tex]
[tex] = 100 - {7}^{18 - 16} [/tex]
[tex] = 100 - {7}^{2} [/tex]
[tex] = 100 - 49[/tex]
[tex] = 51[/tex]
[tex]4)n = {3}^{19} - {3}^{17} + {3}^{16} [/tex]
[tex]n = {3}^{16} ( {3}^{3} - 3 + 1)[/tex]
[tex]n = {3}^{16} (27 - 3 + 1)[/tex]
[tex]n = {3}^{16} (24 + 1)[/tex]
[tex]n = {3}^{16} \times 25[/tex]
[tex]n = {( {3}^{8} )}^{2} \times {5}^{2} [/tex]
[tex]n = {( {3}^{8} \times 5)}^{2} = > p.p[/tex]