Tìm x biết: a, 0,(3)x=669,(6) b, -2/3=27/-8x c,/x-2020/=/x-1/ 18/07/2021 Bởi Cora Tìm x biết: a, 0,(3)x=669,(6) b, -2/3=27/-8x c,/x-2020/=/x-1/
a, 0,(3)x=669,(6) ⇒x=2009 b, $\frac{-2}{3}=$ $\frac{27}{-8x}$ ⇒(-2).(-8x)=3.27 ⇒16x=81 ⇒x=81/16 c, |x-2020|=|x-1| ⇒\(\left[ \begin{array}{l}x-2020=x-1\\x-2020=1-x\end{array} \right.\) +, x-2020=x-1 ⇒x-x=-1+2020 ⇒0=2019 (vô lí ⇒loại) +, x-2020=1-x ⇒x+x=1+2020 ⇒2x=2021 ⇒x=2021/2 Vậy x=2021/2 Bình luận
a, 0,(3)x=669,(6)
⇒x=2009
b, $\frac{-2}{3}=$ $\frac{27}{-8x}$
⇒(-2).(-8x)=3.27
⇒16x=81
⇒x=81/16
c, |x-2020|=|x-1|
⇒\(\left[ \begin{array}{l}x-2020=x-1\\x-2020=1-x\end{array} \right.\)
+, x-2020=x-1
⇒x-x=-1+2020
⇒0=2019 (vô lí ⇒loại)
+, x-2020=1-x
⇒x+x=1+2020
⇒2x=2021
⇒x=2021/2
Vậy x=2021/2