[tex] {(12 - 3)}^{2} \times {(6 + 3)}^{18} - {9}^{20} = {9}^{2} \times {9}^{18} - {9}^{20} = {9}^{2 + 1} - {9}^{20} = {9}^{20} - {9}^{20} = 0[/tex]
[tex] {( {4}^{2} \div {2}^{2} ) }^{2} \times {4}^{18} \div {256}^{5} = {(16 \div 4)}^{2} \times {4}^{18} \div { ({4}^{4}) }^{5} = {4}^{2} \times {4}^{18} \div {4}^{4 \times 5} = {4}^{2 + 18} \div {4}^{20} = {4}^{20} \div {4}^{20} = 1[/tex]
