5x^2 - 10x + 17
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x + 2 | 5x^3 + 0x^2 + 7x + 5 how does x becomes 5x^3
-(5x^3 + 10x^2)
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- 10x^2 + 7x How does x become -10x
-(- 10x^2 - 10x )
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17x + 5 How does x become 17x
-( 17x + 34)
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-29
remainder is -29/(x+2)