sos !!!
`#3107.101107`
`b,`
\(x^{15}-8x^{14}+8x^{13}-8x^{12}+...-8x^2+8x-5\)
Ta thấy: `8 = 7 + 1 = x + 1`
Thay `8 = x + 1` vào, ta có:
\(x^{15}-\left(x+1\right)x^{14}+\left(x+1\right)x^{13}-\left(x+1\right)x^{12}+...-\left(x+1\right)x^2+\left(x+1\right)x-5\)
\(=x^{15}-x^{15}-x^{14}+x^{14}+x^{13}-...-x^3-x^2+x^2+x-5\)
\(=x-5=7-5=2.\)
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