SOLUTION: Solve the equation 3x^4-11x^2-20=0 81x^4=16 4x^3-8x^2-x+2=0

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Question 133285: Solve the equation
3x^4-11x^2-20=0
81x^4=16
4x^3-8x^2-x+2=0
Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Given: +3x%5E4-11x%5E2-20=0+
%283x+%2B+4%29+%28x+-5%29+
x = -4/3 and x = 5
Given: 81x%5E4=16
Take the quad root of each side
3%5E4+%2A+x%5E4+=+2%5E4+
3x+=+2
x = 2/3
Given: +4x%5E3-8x%5E2-x%2B2=0
4x%5E2%28x+-2%29+-+%28x-2%29+=+0+
+%284x%5E2+-1%29+%28x-2%29+=+0
%282x-1%29%282x%2B1%29+%28x-2%29+=+0+
x = 1/2, -1/2 , 2