B=5 phan 1.6+5 phan6.11+5 phan 5x+1(6x+6)=2005 phan 2006 BAI VE PHAN SO NHA 15/11/2021 Bởi Josie B=5 phan 1.6+5 phan6.11+5 phan 5x+1(6x+6)=2005 phan 2006 BAI VE PHAN SO NHA
`B= 5/(1.6) + 5/(6.11) + …+ 5/((5x+1)(5x+6)) = 2005/2006` `B=1/1 – 1/6 + 1/6 – 11+…+ 1/(5x+1) – 1/(5x+6) = 2005/2006` `B=1 – 1/(5x+6) = 2005/2006` `B=1/(5x+6) = 1 – 2005/2006` `B= 1/(5x+6) = 1/2006` `=> 5x+6=2006` `=> 5x=2000` `=> x=400` Bình luận
Đáp án: Giải thích các bước giải: $\dfrac{5}{1.6}$$+$$\dfrac{5}{6.11}$$+$$…$$+$$\dfrac{5}{(5x+1)(5x+6)}$$=$$\dfrac{2005}{2006}$ $ $ $⇒1-\dfrac{1}{6}+\dfrac{1}{6}-\dfrac{1}{11}+…+\dfrac{1}{5x+1}-\dfrac{1}{5x+6}=\dfrac{2005}{2006}$ $ $ $⇒1-\dfrac{1}{5x+6}=\dfrac{2005}{2006}$ $ $ $⇒\dfrac{1}{5x+6}=\dfrac{1}{2006}$ $ $ $⇒5x+6=2006$ $⇒5x=2000$ $⇒x=400$ Bình luận
`B= 5/(1.6) + 5/(6.11) + …+ 5/((5x+1)(5x+6)) = 2005/2006`
`B=1/1 – 1/6 + 1/6 – 11+…+ 1/(5x+1) – 1/(5x+6) = 2005/2006`
`B=1 – 1/(5x+6) = 2005/2006`
`B=1/(5x+6) = 1 – 2005/2006`
`B= 1/(5x+6) = 1/2006`
`=> 5x+6=2006`
`=> 5x=2000`
`=> x=400`
Đáp án:
Giải thích các bước giải:
$\dfrac{5}{1.6}$$+$$\dfrac{5}{6.11}$$+$$…$$+$$\dfrac{5}{(5x+1)(5x+6)}$$=$$\dfrac{2005}{2006}$
$ $
$⇒1-\dfrac{1}{6}+\dfrac{1}{6}-\dfrac{1}{11}+…+\dfrac{1}{5x+1}-\dfrac{1}{5x+6}=\dfrac{2005}{2006}$
$ $
$⇒1-\dfrac{1}{5x+6}=\dfrac{2005}{2006}$
$ $
$⇒\dfrac{1}{5x+6}=\dfrac{1}{2006}$
$ $
$⇒5x+6=2006$
$⇒5x=2000$
$⇒x=400$