Question

x^4-1681x^2+129600 find x​

Answer 1

Step-by-step explanation:

${x}^{4} - 1681 {x}^{2} + 129600 = 0$

${x}^{4} - 720 {x}^{2} + (360) {}^{2} - 961 {x}^{2} = 0$

$( {x}^{2} - 360) {}^{2} - {31}^{2} = 0$

$( {x}^{2} - 360 + 31)( {x}^{2} - 360 - 31) = 0$

$( {x}^{2} - 329)( {x}^{2} - 391) = 0$

${x}^{2} = 329 \: \: or \: \: 391$

$x = \sqrt{329} \: \: or \: \: \sqrt{391}$