Question

P_(x)=-80x⁶+80x⁵-80x⁴+...+80x+15 ; x=79

tính P_(x)

Answer 1

Lời giải:

\(P=-80(x^6-x^5+x^4-x^3+x^2-x+1)+95\)

\(=-(x+1)(x^6-x^5+x^4-x^3+x^2-x+1)+95=-(x^7+1)+95\)

\(=-79^7+94\)