Bài 1:
\(a,=15x^2-6x+5x-2=\left(5x-2\right)\left(3x+1\right)\\ b,=4x^2-8x-x+2=\left(x-2\right)\left(4x-1\right)\)
Bài 2:
\(a,\Leftrightarrow\left(x^2-1\right)^3:\left(x^2-1\right)^2=8\\ \Leftrightarrow x^2-1=8\\ \Leftrightarrow x^2=9\Leftrightarrow x=\pm3\\ b,\Leftrightarrow3x^2-5x+2=0\\ \Leftrightarrow\left(x-1\right)\left(3x-2\right)=0\Leftrightarrow\left[{}\begin{matrix}x=1\\x=\dfrac{2}{3}\end{matrix}\right.\\ c,\Leftrightarrow x^3+8-x^3-2x=15\\ \Leftrightarrow-2x=7\Leftrightarrow x=-\dfrac{7}{2}\\ d,\Leftrightarrow x^4-x^2+4x^2-4=0\\ \Leftrightarrow\left(x^2+4\right)\left(x^2-1\right)=0\\ \Leftrightarrow\left(x-1\right)\left(x+1\right)\left(x^2+4\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=1\\x=-1\end{matrix}\right.\)
Bài 2:
c: \(\Leftrightarrow x^3+8-x^3-2x=15\)
hay \(x=-\dfrac{7}{2}\)
