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$ b){(x - 16)^2} - 16 = 0 \\ \Leftrightarrow {(x - 16)^2} = 16 \\ \Leftrightarrow \left[ {\begin{array}{*{20}{c}} {x - 16 = 4} \\ {x - 16 = - 4} \end{array}} \right. \\ \Leftrightarrow \left[ {\begin{array}{*{20}{c}} {x = 20} \\ {x = 12} \end{array}} \right. \\ c)\dfrac{x}{4} + \dfrac{2}{5}.(x - 2) = \dfrac{{ - 7}}{{10}} \\ \Leftrightarrow \dfrac{x}{4} + \dfrac{{2{\text{x}}}}{5} - \dfrac{4}{5} = \dfrac{{ - 7}}{{10}} \\ \Leftrightarrow \dfrac{{13}}{{20}}x = \dfrac{{ - 7}}{{10}} + \dfrac{4}{5} \\ \Leftrightarrow \dfrac{{13}}{{20}}x = \dfrac{1}{{10}} \\ \Rightarrow x = \dfrac{1}{{10}}:\dfrac{{13}}{{20}} \\ \Rightarrow x = \dfrac{2}{{13}} \\ d)\dfrac{{x + 5}}{3} + \dfrac{{x + 5}}{{15}} + \dfrac{{x + 5}}{{35}} + \dfrac{{x + 5}}{{63}} + \dfrac{{x + 5}}{{99}} = \dfrac{{20}}{{11}} \\ \Leftrightarrow \dfrac{{x + 5}}{{1.3}} + \dfrac{{x + 5}}{{3.5}} + \dfrac{{x + 5}}{{5.7}} + \dfrac{{x + 5}}{{7.9}} + \dfrac{{x + 5}}{{9.11}} = \dfrac{{20}}{{11}} \\ \Leftrightarrow \dfrac{{x + 5}}{2}\left( {1 - \dfrac{1}{3} + \dfrac{1}{3} - \dfrac{1}{5} + ... + \dfrac{1}{9} - \dfrac{1}{{11}}} \right) = \dfrac{{20}}{{11}} \\ \Leftrightarrow \dfrac{{x + 5}}{2}.\dfrac{{10}}{{11}} = \dfrac{{20}}{{11}} \\ \Rightarrow x + 5 = 4 \\ \Leftrightarrow x = 4 - 5 \\ \Leftrightarrow x = - 1 \\ e)\dfrac{3}{4}(x - 1) + 1\dfrac{3}{5}x - 30\% = - 2\dfrac{4}{{15}} \\ \Leftrightarrow \dfrac{3}{4}x - \dfrac{3}{4} + \dfrac{8}{5}x - \dfrac{3}{{10}} = \dfrac{{ - 34}}{{15}} \\ \Leftrightarrow \dfrac{{47}}{{20}}x = \dfrac{{ - 73}}{{60}} \\ \Rightarrow x = \dfrac{{ - 73}}{{60}}:\dfrac{{47}}{{20}} \\ \Rightarrow x = \dfrac{{ - 73}}{{141}} \\ $
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