[tex] {3}^{21} \times {5}^{21} - {15}^{21} = {(3 \times 5)}^{21} - {15}^{21} = {15}^{21} - {15}^{21} = 0[/tex]
[tex] {3}^{20} \times {2}^{20} - {6}^{23} \div {6}^{3} = {(3 \times 2)}^{20} - {6}^{23} \div {6}^{3} = {6}^{20} - {6}^{20} = 0[/tex]
[tex] {2}^{18} \times {12}^{18} \div ( {6}^{16} \times {4}^{16} ) = {24}^{18} \div {24}^{16} = {24}^{2} = 576[/tex]
[tex] {75}^{38} \div {25}^{38} - { ({3}^{19}) }^{2} = {3}^{38} - {3}^{38} = 0[/tex]
[tex] {26}^{27} \div {13}^{27} \div {2}^{ {5}^{2} } = {2}^{27} \div {2}^{25} = {2}^{2} = 4[/tex]
[tex] {10}^{64} \div {2}^{64} - {5}^{ {4}^{3} } = {5}^{64} - {5}^{64} = 0[/tex]