x^4 - 41x^2 + 400 = 0 Let z = x^2
z^2 - 41z + 400 = 0
(z - 25)(z - 16) = 0
Now put the x^2 back in
(x^2 - 25)(x^2 - 16) = 0
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x^2 - 25 = 0
x = +/- 5
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x^2 - 16 = 0
x = +/- 4
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Question 2
-3 || 1 -2 0 -4 4 ||
-3 15 -45 147
========================= =
1 -5 15 -49 151
The answer is 151 just as it should be
