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If a/b+b/a=\ -1, then a^3-b^3=? (a)1 ...

If `a/b+b/a=\ -1,` then `a^3-b^3=?` (a)1 (b) `-1` (c) `1/2` (d) 0

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`a/b+b/a=-1`
Multiply each term by `ab`
`a^2+b^2=-ab`
Now,` a^3-b^3=(a-b)(a^2+b^2+ab)`
`=(a-b)(-ab+ab)`
`=(a-b) xx 0`
`=0`
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