Найдите корни уравнения, помогите пожалуйста))

$(x^{2} +2x) ^{2} -2(x+2)( x^{2} -x)-15( x^{2} -2x+1)=0 \\\\ (x^{2} +2x) ^{2} -2x(x+2)( x -1)-15( x -1)^2=0 \\\\(x^{2} +2x) ^{2} -2(x^2+2x)( x -1)-15( x -1)^2=0 \\\\(x^{2} +2x) ^{2} -2(x^2+2x)( x -1)+( x -1)^2-16( x -1)^2=0 \\\\((x^{2} +2x)-(x-1))^2-16( x -1)^2=0 \\\\(x^{2} +x+1)^2-16( x -1)^2=0 \\\\(x^{2} +x+1)^2=16( x -1)^2$

$\frac{(x^{2} +x+1)^2}{( x -1)^2}=16 \\\\(\frac{x^{2} +x+1}{x -1})^2=16 \\\\\frac{x^{2} +x+1}{x -1}=\frac{+}{}4$

$\left \{ {{\frac{x^{2} +x+1}{x -1}=4} \atop {\frac{x^{2} +x+1}{x -1}=-4}} \right. \\\\ \left \{ {{x^{2} +x+1=4(x-1)} \atop {x^{2} +x+1=-4(x-1)}} \right. \\\\ \left \{ {{x^{2} +x+1=4x-4} \atop {x^{2} +x+1=-4x+4}} \right. \\\\ \left \{ {{x^{2} +x+1-4x+4=0} \atop {x^{2} +x+1+4x-4=0}} \right. \\\\ \left \{ {{x^{2} -3x+5=0} \atop {x^{2} +5x-3=0}} \right.$

$x^{2} -3x+5=0 \\\\D = 9 - 5*4 = -11$

Действительных корней нет

$x^{2} +5x-3=0 \\\\D = 25 +12 = 37 \\\\x_1 = \frac{-5-\sqrt{37}}{2} \\\\x_2 = \frac{-5+\sqrt{37}}{2}$