x-(25%)^2x=`1/2`-1`3/4` (1,4x-6):`2/3`=-3-1`1/5`

0 bình luận về “x-(25%)^2x=`1/2`-1`3/4` (1,4x-6):`2/3`=-3-1`1/5`”

1. Giải thích các bước giải:

   a) 

   x – `(25%)^2`x = `1/2`-1`3/4`

   => x – `(1/4)^2`x = `1/2` – `7/4` = `-5/4`

   => x – `1/16`x  = `-5/4`

   =>x . (1-`1/16`) = `-5/4`

   => x = `-5/4` : `15/16`

   =>x= `-4/3`

   b)

   (1,4 x – 6) : `2/3` = -3 – 1`1/5`

   =>(1,4 x – 6) : `2/3` = -3 – 1,2 

   =>(1,4 x – 6) : `2/3` = -4,2

   =>1,4 x – 6 = -4,2 . 2/3 = -2,8

   =>1,4 x = -2,8 + 6 = 3,2

   =>x = 3,2 : 1,4

   =>x ≈ 2.3

   Bình luận

2. x – (25%)² . x = $\frac{1}{2}$ – 1$\frac{3}{4}$ 

   x – ($\frac{1}{4}$)² . x = $\frac{1}{2}$ – $\frac{7}{4}$

   x – $\frac{1}{16}$ . x = $\frac{4}{8}$ – $\frac{14}{8}$

   x . (1 – $\frac{1}{16}$) = $\frac{-5}{4}$

   x . $\frac{15}{16}$ = $\frac{-5}{4}$

   x = $\frac{-5}{4}$ : $\frac{15}{16}$

   x = $\frac{-4}{3}$

   Vậy x = $\frac{-4}{3}$

   (1,4 . x – 6) : $\frac{2}{3}$ = -3 – 1$\frac{1}{5}$

   ($\frac{7}{5}$ . x – 6) : $\frac{2}{3}$ = -3 – $\frac{6}{5}$

   ($\frac{7}{5}$ . x – 6) : $\frac{2}{3}$ = $\frac{-21}{5}$

   $\frac{7}{5}$ . x – 6 = $\frac{-21}{5}$ . $\frac{2}{3}$ 

   $\frac{7}{5}$ . x – 6 = $\frac{-14}{5}$

   $\frac{7}{5}$ . x = $\frac{-14}{5}$ + 6

   $\frac{7}{5}$ . x = $\frac{16}{5}$

   x = $\frac{16}{5}$ : $\frac{7}{5}$

   x = $\frac{16}{7}$

   Vậy x = $\frac{16}{7}$

   Bình luận