Tìm x , biết :

a) x + 2/3 = -3/4

b) 5/4 - x = -3/2

c) -6/5 - x = 2/7 - (-3/7)

Giải từng bươc và giải thích rõ

Đáp án:

Giải thích các bước giải:

$\text{a) x + $\dfrac{2}{3}$ = $\dfrac{-3}{4}$}$

$\text{ $\Rightarrow$ x = $\dfrac{-3}{4}$ - $\dfrac{2}{3}$}$

$\text{$\Rightarrow$ x = $\dfrac{-17}{12}$}$

$\text{b) $\dfrac{5}{4}$ - x = $\dfrac{-3}{2}$}$

$\text{ $\Rightarrow$ x = $\dfrac{5}{4}$ + $\dfrac{3}{2}$}$

$\text{ $\Rightarrow$ x = $\dfrac{11}{4}$}$

$\text{c) $\dfrac{-6}{5}$ - x = $\dfrac{2}{7}$ - $\dfrac{-3}{7}$}$

$\text{ $\Rightarrow$ $\dfrac{-6}{5}$ - x = $\dfrac{2}{7}$ + $\dfrac{3}{7}$}$

$\text{$\Rightarrow$ $\dfrac{-6}{5}$ - x = $\dfrac{5}{7}$}$

$\text{$\Rightarrow$ x = $\dfrac{-6}{5}$ - $\dfrac{5}{7}$}$

$\text{$\Rightarrow$ x = $\dfrac{-67}{35}$}$

Đáp án:

` a, x + 2/3 = -3/4 `

` x = -3/4 - 2/3 `

` x = -17/12 `

` b, 5/4 - x = -3/2 `

` x = 5/4 - ( -3/2 ) `

` x = 5/4 + 3/2 `

` x = 11/4 `

` c, -6/5 - x = 2/7 - ( - 3/7 ) `

` -6/5 - x = 2/7 + 3/7 `

` -6/5 - x = 5/7 `

` x = - 6/5 - 5/7 `

` x = -67/35 = -1 32/35 `

` #AkiSha2007 `