SOLUTION: this is a four answer question. I found one of the answers by just guessing but I don't know how the operations work on a problem like this so can someone please eplain this to me?

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Question 16274: this is a four answer question. I found one of the answers by just guessing but I don't know how the operations work on a problem like this so can someone please eplain this to me? x%5E4-10x%5E2=9=0 enter them in increasing order: x1= __ x2= __ x3= __ x4=3
Found 2 solutions by Earlsdon, tjnw79:
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Solve:
x%5E4+-+10x%5E2+%2B+9+=+0 This can be factored by treating the x^4 as (x^2)^2.
%28x%5E2%29%5E2+-+10%28x%5E2%29+%2B+9+=+0
%28x%5E2+-+1%29%28x%5E2+-+9%29+=+0 Apply the zero products principle.
x%5E2+-+1+=+0 and/or x%5E2+-+9+=+0
If x%5E2+-+1+=+0, then x%5E2+=+1 and x+=+%2B1 or x+=+-1
If x%5E2+-+9+=+0, then x%5E2+=+9 and x+=+3 or x+=+-3
The four roots are:
x = -1
x = 1
x = -3
x = 3
So, in increasing order, we have:
x1 = -3
x2 = -1
x3 = 1
x4 = 3


Answer by tjnw79(57) About Me  (Show Source):