# Math

For Reiny:What step did I do wrong.(Help)

(x-4x^3)^2
=(x-4x^3)(x-4x^3)=(x)(x)+(x)(-4x^3)+(-4x^3)(x)+(-4x^3)(4x^3)

= x^2-4x^4-4x^4-16x^6
=x^2-8x^4-16x^6

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3. 👁 90

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posted by Reiny
2. -16x^2=>+16x^2

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3. should have looked a bit more carefully

the last term should be + 16x^6

(in your second line: should have been

=(x-4x^3)(x-4x^3)=(x)(x)+(x)(-4x^3)+(-4x^3)(x)+(-4x^3)(-4x^3)

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posted by Reiny
4. Thanks Reiny, Thanks Anonymous I went over it and found the problem.

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