X^4-7x^2+6=0 помогите решить

Пусть t=x² Тогда  t²-7t+6=0 D = 7²- 6·4 = 25 [latex] \left[\begin{array}{c}t = \frac{7 + 5}{2} \\t = \frac{7 - 5}{2}\end{array}[/latex] [latex]\left[\begin{array}{c}t = 6 \\t = 1\end{array}[/latex] [latex]\left[\begin{array}{c} x^{2} = 6 \\ x^{2} = 1\end{array}[/latex] [latex]\left[\begin{array}{c}x=-1\\x=1\\x=6\\x=-6\end{array}[/latex]