SOLUTION: Would you please help me with this? Factor 63c^4+36c^2-18 Thank you!

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Question 204049: Would you please help me with this?
Factor
63c^4+36c^2-18
Thank you!
Found 2 solutions by scott8148, josmiceli:
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
9 (7c^4 + 4c^2 - 2)

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
I'll say x+=+c%5E2, then
63c%5E4%2B36c%5E2-18+=+63X%5E2+%2B+36X+-+18
To find factors,
63x%5E2+%2B+36x+-+18+=+0
Divide both sides by 9
7x%5E2+%2B+4x+-+2+=+0
quadratic formula:
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
a+=+7
b+=+4
c+=+-2
x+=+%28-4+%2B-+sqrt%28+4%5E2-4%2A7%2A%28-2%29+%29%29%2F%282%2A7%29+
x+=+%28-4+%2B-+sqrt%28+16+%2B+56+%29%29%2F14+
x+=+%28-4+%2B-+sqrt%28+72+%29%29%2F14+
x+=+%28-4+%2B-+6%2Asqrt%28+2+%29%29%2F14+
x+=+%28-2+%2B+3%2Asqrt%28+2+%29%29%2F7+
and
x+=+%28-2+-+3%2Asqrt%28+2+%29%29%2F7+
And, since x+=+c%5E2,
c+=+sqrt%28%28-2+-+3%2Asqrt%28+2+%29%29%2F7%29+
also
c+=+sqrt%28%28-2+%2B+3%2Asqrt%28+2+%29%29%2F7%29+
The factors are:
c+-+sqrt%28%28-2+-+3%2Asqrt%28+2+%29%29%2F7%29+,
c+%2B+sqrt%28%28-2+-+3%2Asqrt%28+2+%29%29%2F7%29+,
c+-+sqrt%28%28-2+%2B+3%2Asqrt%28+2+%29%29%2F7%29+
c+%2B+sqrt%28%28-2+%2B+3%2Asqrt%28+2+%29%29%2F7%29+
Unless I goofed, but I think method is OK