\(x^4-2x^2-144x-1295=0\)
\(\Leftrightarrow\left(x^4+2x^2+1\right)-\left(4x^2+144x+1296\right)=0\)
\(\Leftrightarrow\left(x^2+1\right)^2-\left(2x+36\right)^2=0\)
\(\Leftrightarrow\left(x^2+1+2x+36\right)\left[x^2+1-\left(2x+36\right)\right]=0\)
\(\Leftrightarrow\left(x^2+2x+37\right)\left(x^2-2x-35\right)=0\)
\(\Leftrightarrow\left(x^2+5x-7x-35\right)\left(x^2+2x+1+36\right)=0\)
\(\Leftrightarrow\left[x\left(x+5\right)-7\left(x+5\right)\right]\left[\left(x+1\right)^2+36\right]=0\)
\(\Leftrightarrow\left(x+5\right)\left(x-7\right)\left[\left(x+1\right)^2+36\right]=0\)
Dễ thấy:\(\left(x+1\right)^2+36\ge36>0\forall x\) (vô nghiệm)
\(\Rightarrow\left[{}\begin{matrix}x+5=0\\x-7=0\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=-5\\x=7\end{matrix}\right.\)