Respostas

2013-11-15T15:13:19-02:00
Pelo termo geral (x-1)^7 quarto termo .

a=x\\  b=-1 \\ n=7 \\ p=3

T_{p+1}=T_4\\p+1=4\\p=3

Substituindo.

T_{p+1}=\binom{n}{p}a^{n-p}b^p

T_4=\binom{7}{3}x^{7-3}.(-1)^3

T_4= \frac{7!}{3!4!} .x^4.-1

\boxed{T_4=-35x^4}

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