Giúp mk vs mn ơi huhu:(( ( Chỉ cần những câu bôi đỏ thôi nhem)

Giải thích các bước giải:

$\begin{array}{l} 10){(x - 2)^3} - (x - 3)({x^2} + 3x + 9) + 6{(x + 1)^2} = 15\\ \Leftrightarrow {x^3} - 6{x^2} + 12x - 8 - \left( {{x^3} - 27} \right) + 6({x^2} + 2x + 1) = 15\\ \Leftrightarrow {x^3} - 6{x^2} + 12x - 8 - {x^3} + 27 + 6{x^2} + 12x + 6 = 15\\ \Leftrightarrow 24x + 25 = 15\\ \Leftrightarrow 24x = - 10\\ \Leftrightarrow x = \frac{{ - 5}}{{12}}\\ 12){(x - 2015)^{x + 2}} - {(x - 2015)^{x + 12}} = 0\\ \Leftrightarrow {(x - 2015)^{x + 2}}\left[ {1 - {{\left( {x - 2015} \right)}^{10}}} \right] = 0\\ \Leftrightarrow \left[ \begin{array}{l} {(x - 2015)^{x + 2}} = 0\\ 1 - {\left( {x - 2015} \right)^{10}} = 0 \end{array} \right.\\ \Leftrightarrow \left[ \begin{array}{l} x - 2015 = 0\\ {\left( {x - 2015} \right)^{10}} = 1 \end{array} \right.\\ \Leftrightarrow \left[ \begin{array}{l} x = 2015\\ x - 2015 = 1\\ x - 2015 = - 1 \end{array} \right.\\ \Leftrightarrow \left[ \begin{array}{l} x = 2015\\ x = 2016\\ x = 2014 \end{array} \right.\\ 13){x^3} - 6{x^2} + 5x = 0\\ \Leftrightarrow x({x^2} - 6x + 5) = 0\\ \Leftrightarrow x(x - 1)(x - 5) = 0\\ \Leftrightarrow \left[ \begin{array}{l} x = 0\\ x = 1\\ x = 5 \end{array} \right. \end{array}$