Giúp vs cần rất gấp .Hứa sẽ vote câu trả lời hay nhất ah Cho P(x) =x^5 – 2021x^4 +2021x^3-2021x^2 + 2021x +1 Tính P(2020) 09/10/2021 Bởi Parker Giúp vs cần rất gấp .Hứa sẽ vote câu trả lời hay nhất ah Cho P(x) =x^5 – 2021x^4 +2021x^3-2021x^2 + 2021x +1 Tính P(2020)
Đáp án+Giải thích các bước giải: `x=2020=>x+1=2021` `=>P(2020)=x^5-(x+1)x^4+(x+1)x^3-(x+1)x^2+(x+1)x+1` `=x^5-x^5-x^4+x^4+x^3-x^3-x^2+x^2+x+1` `=x+1` `=2021` Bình luận
$P(x)=x^5-2021x^4+2021x^3-2021x^2+2021x+1$ $=x^5-x^4-2020x^4+2020x^3+x^3-x^2-2020x^2+2020x+x+1$ $=(x^5-2020x^4)-(x^4-2020x^3)+(x^3-2020x^2)-(x^2-2020x)+x-2020+2021$ $=x^4(x-2020)-x^3(x-2020)+x^2(x-2020)-x(x-2020)+(x-2021)+2021$ $=(x-2020)(x^4-x^3+x^2-x+1)+2021$ $P(2020)=(2020-2020)(2020^4-2020^3+2020^2-2020+1)+2021$ $=0+2021=2021$ Bình luận
Đáp án+Giải thích các bước giải:
`x=2020=>x+1=2021`
`=>P(2020)=x^5-(x+1)x^4+(x+1)x^3-(x+1)x^2+(x+1)x+1`
`=x^5-x^5-x^4+x^4+x^3-x^3-x^2+x^2+x+1`
`=x+1`
`=2021`
$P(x)=x^5-2021x^4+2021x^3-2021x^2+2021x+1$
$=x^5-x^4-2020x^4+2020x^3+x^3-x^2-2020x^2+2020x+x+1$
$=(x^5-2020x^4)-(x^4-2020x^3)+(x^3-2020x^2)-(x^2-2020x)+x-2020+2021$
$=x^4(x-2020)-x^3(x-2020)+x^2(x-2020)-x(x-2020)+(x-2021)+2021$
$=(x-2020)(x^4-x^3+x^2-x+1)+2021$
$P(2020)=(2020-2020)(2020^4-2020^3+2020^2-2020+1)+2021$
$=0+2021=2021$