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may someone help me ASAP? I am solving polynomial equations and I don't know how to do it, here is the equation... x^4+11x^2=3x^2+128

Respuesta :

Answer:

[tex]x=2\sqrt{2}[/tex], [tex]x=-2\sqrt{2}[/tex], [tex]x=4i[/tex], [tex]x=-4i[/tex]

Step-by-step explanation:

[tex]x^4+11x^2=3x^2+128[/tex]

First, we subtract 128 from both sides:

[tex]x^4+11x^2-128=3x^2[/tex]

Then, we subtract [tex]3x^2[/tex] from both sides:

[tex]x^4+8x^2-128=0[/tex]

Rewrite the equation:

[tex]u^2+8u-128=0[/tex]

Insert and solve:

[tex]u^2+8u-128=0\\u=8,u=-16\\x^2=8:x=2\sqrt{2},x= -2\sqrt{2} \\x^2=-16:x=4i,x=-4i[/tex]

Please give Brainliest