Можете пожалуйста помочь с свойствами степенями?Четвёртое - это не свойства, а...

Решите задачу:

$1) {a}^{ \frac{2}{5} } \times {a}^{ - 1} = | {a}^{n} \times {a}^{m} = {a}^{n + m}| = {a}^{ \frac{2}{5} + ( - 1) } = {a}^{ \frac{2}{5} - 1} = {a}^{ - \frac{3}{5} } = \frac{1}{ {a}^{ \frac{3}{5} } }$
${b}^{ - 3.1} \times {b}^{0.7} = {b}^{ - 3.1 + 0.7} = {b}^{ - 2.4} = \frac{1}{ {b}^{2.4} }$
$2) {x}^{ \frac{3}{7}} \div {x}^{ - 2} = | {a}^{n} \div {a}^{m} = {a}^{n - m} | = {x}^{ \frac{3}{7} - ( - 2)} = {x}^{ \frac{3}{7} + 2 } = {x}^{2 \frac{3}{7} }$
${y}^{ - 0.4} \div {y}^{ - 1} = {y}^{ - 0.4 + 1} = {y}^{0.6}$
$3)( {c}^{ - 7} )^{ \frac{2}{7} } = |( {a}^{n} )^{m} = {a}^{n \times m} | = {c}^{ - 7 \times \frac{2}{7} } = {c}^{ - 2} = \frac{1}{ {c}^{2} }$
$( {d}^{ - 0.1} )^{ - 4} = {d}^{ - 0.1 \times ( - 4)} = {d}^{0.4}$
$4) {2}^{5 - 2x} = 64 \\ {2}^{5 - 2x} = {2}^{6} \\ 5 - 2x = 6 \\ 2x = - 1 \\ x = - 0.5$
${3}^{3x - 1} = 27 \\ {3}^{3x - 1} = {3}^{3} \\ 3x - 1 = 3 \\ 3x = 4 \\ x = \frac{4}{3} = 1 \frac{1}{3}$