Question

c= x^7 -26x^6+27x^5-47x^4-77x^3+50x^2+x-24 tại x =25

Answer 1

\(C=x^7-26x^6+27x^5-47x^4-77x^3+50x^2+x-24\)

\(=x^7-\left(25+1\right)x^6+\left(25+2\right)x^5-\left(2.25-3\right)x^4-\left(3.25+2\right)x^3+2.25x^2+x-24\)

\(=x^7-\left(x+1\right)x^6+\left(x+2\right)x^5-\left(2x-3\right)x^4-\left(3x+2\right)x^3+2x^3+25-24\) (vì \(x=25\))

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

\(=1\)