Question

Answer 1

\(x=25\Rightarrow x-25=0\)

\(C\left(x\right)=\left(x^7-25x^6\right)+\left(-x^6+25x^5\right)+\left(2x^5-50x^4\right)+\left(3x^4-75x^3\right)+\left(-2x^3+50x^2\right)+x-25+1\)

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

\(=1\)