tìm x lớp 6 nha $\frac{3.x}{2.5}$+$\frac{3.x}{8.11}$+$\frac{3.x}{11.14}$=$\frac{1}{21}$ 27/11/2021 Bởi Abigail tìm x lớp 6 nha $\frac{3.x}{2.5}$+$\frac{3.x}{8.11}$+$\frac{3.x}{11.14}$=$\frac{1}{21}$
$\dfrac{3x}{2.5}+\dfrac{3}{8.11}+\dfrac{3.x}{11.14}=\dfrac{1}{21}$ $ ⇔ x.(\dfrac{1}{2}-\dfrac{1}{14}) = \dfrac{1}{21}$ $⇔ x . \dfrac{3}{7} = \dfrac{1}{21}$ $⇔ x= \dfrac{1}{9}$ Bình luận
`(3x)/2.5+(3x)/8.11+(3x)/11.14=1/21` `=> 3x.(1/2.5+1/8.11+1/11.14)=1/21` `=>3x.(1/10 + 1/88 + 1/154)=1/21“ `=>3x.(308/3080+35/3080+20/3080)=1/21` `=>3x. 33/280=1/21` `⇒ x = 1/21 : 33/280 :3` `⇒ x = 1/21 . 280/33 . 1/3` `⇒ x = 40/297` Bình luận
$\dfrac{3x}{2.5}+\dfrac{3}{8.11}+\dfrac{3.x}{11.14}=\dfrac{1}{21}$
$ ⇔ x.(\dfrac{1}{2}-\dfrac{1}{14}) = \dfrac{1}{21}$
$⇔ x . \dfrac{3}{7} = \dfrac{1}{21}$
$⇔ x= \dfrac{1}{9}$
`(3x)/2.5+(3x)/8.11+(3x)/11.14=1/21`
`=> 3x.(1/2.5+1/8.11+1/11.14)=1/21`
`=>3x.(1/10 + 1/88 + 1/154)=1/21“
`=>3x.(308/3080+35/3080+20/3080)=1/21`
`=>3x. 33/280=1/21`
`⇒ x = 1/21 : 33/280 :3`
`⇒ x = 1/21 . 280/33 . 1/3`
`⇒ x = 40/297`