[tex]{2}^{53} \div {2}^{40} \\ = {2}^{53 - 40} \\ = {2}^{13} \\ \\ \\ \\ {2}^{83} \div {2}^{70} \\ = {2}^{83 - 70} \\ = {2}^{1 3} \\ \\ \\ {2}^{70} \div {8}^{23} \\ = {2}^{70} \div ( {2}^{3}) {}^{23} \\ = {2}^{70} \div {2}^{69} \\ = {2}^{70 - 69} \\ = {2}^{1} \\ = 2 \\ \\ {3}^{60} \div {81}^{15} \\ = {3}^{60} \div ( {3}^{4} ) ^{15} \\ = {3}^{60} \div {3}^{60} \\ = 1 \\ \\ ( {2}^{7} ) ^{10} \\ = {2}^{7 \times 10} \\ = {2}^{70} \\ \\ ( {5}^{3} ) ^{4} \\ = {5}^{3 \times 4} \\ = {5}^{12} \\ \\ {2}^{20} \div {5}^{20} \\ = {0.4}^{2} \\ \\ {12}^{30} \div {6}^{30} \\ = {2}^{30} [/tex]
