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Question
By using identity evaluate the following:
`1 + 1/8 - 27/8`
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Solution
We know that a3 + b3 + c3 = 0 then a + b + c = 3abc
`1 + 1/8 - 27/8 = 1^3 + (1/2)^3 - (3/2)^3`
a + b + c = `1 + 1/2 - 3/2`
= `(2 + 1 - 3)/2`
= `0/2`
= 0
`1 + 1/8 - 27/8 = 3(1) xx 1/2 xx ((-3)/2)`
= `(-9)/4`
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