Question

x^5-5x+5x^3-5x^2+5x-1 với x=4

Answer 1

Tại \(x=4\)thì:

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

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

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

= \(3\)

Answer 2

mình chỉnh lại đề nhé:

Do:  \(x=4\)\(\Rightarrow\)\(x+1=5\)

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

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

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

\(=x-1\)

\(=4-1=3\)

Answer 3

Thế 4 vô x ta được =4^5-20+5.4^3-5.4^2+5.4-1 =4^5-20+5.(4^3-4^2+4)-1 =4^5-20+5.52-1 =1024-20+260-1 =1263