$\frac{x-241}{17}$ +$\frac{x-220}{19}$+$\frac{x-195}{21}$+$\frac{x-166}{23}$=10 25/07/2021 Bởi Katherine $\frac{x-241}{17}$ +$\frac{x-220}{19}$+$\frac{x-195}{21}$+$\frac{x-166}{23}$=10
$\frac{x-241}{17}$+$\frac{x-220}{19}$+ $\frac{x-195}{21}$+$\frac{x-166}{23}$ =$10$ ⇔($\frac{x-241}{17}$-1)+ ($\frac{x-220}{19}$-2)+ ($\frac{x-195}{21}$-3)+ ($\frac{x-166}{23}$-4)=0 ⇔$\frac{x-258}{17}$+$\frac{x-258}{19}$+ $\frac{x-258}{21}$+ $\frac{x-258}{23}$ =0 ⇔$(x-258)$.($\frac{1}{17}$+$\frac{1}{19}$+$\frac{1}{21}$+$\frac{1}{23}$)=0 $⇔x-258=0$ $⇔x=258$ Bình luận
`(x-241)/17 +(x-220)/19 +(x-195)/21 +(x-166)/23=10` `⇒ (x-241)/17-1+ (x-220)/19-2+ (x-195)/21-3 +(x-166)/23-4=0` `⇒(x-258)/17+(x-258)/19+(x-258)/21+(x-258)/23=0` `⇒(x-258)(1/17+1/19+1/21+1/23)=0` `⇒x-258=0` (vì `1/17+1/19+1/21+1/23 \ne 0`) `⇒x=258` Bình luận
$\frac{x-241}{17}$+$\frac{x-220}{19}$+ $\frac{x-195}{21}$+$\frac{x-166}{23}$ =$10$
⇔($\frac{x-241}{17}$-1)+ ($\frac{x-220}{19}$-2)+ ($\frac{x-195}{21}$-3)+ ($\frac{x-166}{23}$-4)=0
⇔$\frac{x-258}{17}$+$\frac{x-258}{19}$+ $\frac{x-258}{21}$+ $\frac{x-258}{23}$ =0
⇔$(x-258)$.($\frac{1}{17}$+$\frac{1}{19}$+$\frac{1}{21}$+$\frac{1}{23}$)=0
$⇔x-258=0$
$⇔x=258$
`(x-241)/17 +(x-220)/19 +(x-195)/21 +(x-166)/23=10`
`⇒ (x-241)/17-1+ (x-220)/19-2+ (x-195)/21-3 +(x-166)/23-4=0`
`⇒(x-258)/17+(x-258)/19+(x-258)/21+(x-258)/23=0`
`⇒(x-258)(1/17+1/19+1/21+1/23)=0`
`⇒x-258=0` (vì `1/17+1/19+1/21+1/23 \ne 0`)
`⇒x=258`