Câu hỏi của Lê Phương Linh

Question

Tìm x:

a) $-\dfrac{4}{7}$ - x = $\dfrac{3}{5}$ - 2x

b) ($\dfrac{3}{8}$ - $\dfrac{1}{5}$) + ($\dfrac{5}{8}$ - x) = $\dfrac{1}{5}$

Sahara · Accepted Answer

a/$-\dfrac{4}{7}-x=\dfrac{3}{5}-2x$$\Rightarrow-\dfrac{4}{7}-\dfrac{3}{5}=-2x+x$$\Rightarrow-\dfrac{41}{35}=-x$$\Rightarrow x=\dfrac{41}{35}$Vậy ...b/$\left(\dfrac{3}{8}-\dfrac{1}{5}\right)+\left(\dfrac{5}{8}-x\right)=\dfrac{1}{5}$$\Rightarrow\left(\dfrac{3}{8}+\dfrac{5}{8}\right)-\dfrac{1}{5}-x=\dfrac{1}{5}$$\Rightarrow1-\dfrac{1}{5}-x=\dfrac{1}{5}$$\Rightarrow\dfrac{4}{5}-x=\dfrac{1}{5}$$\Rightarrow x=\dfrac{3}{5}$Vậy ...#kễnhCâu trả lời: a/$-\dfrac{4}{7}-x=\dfrac{3}{5}-2x$$\Rightarrow-\dfrac{4}{7}-\dfrac{3}{5}=-2x+x$$\Rightarrow-\dfrac{41}{35}=-x$$\Rightarrow x=\dfrac{41}{35}$Vậy ...b/$\left(\dfrac{3}{8}-\dfrac{1}{5}\right)+\left(\dfrac{5}{8}-x\right)=\dfrac{1}{5}$$\Rightarrow\left(\dfrac{3}{8}+\dfrac{5}{8}\right)-\dfrac{1}{5}-x=\dfrac{1}{5}$$\Rightarrow1-\dfrac{1}{5}-x=\dfrac{1}{5}$$\Rightarrow\dfrac{4}{5}-x=\dfrac{1}{5}$$\Rightarrow x=\dfrac{3}{5}$Vậy ...#kễnh

Nguyễn Đăng Nhân · Answer

$-\dfrac{4}{7}-x=\dfrac{3}{5}-2x$

$-\dfrac{4}{7}=\dfrac{2}{5}-2x+x$

$\dfrac{2}{5}-x=-\dfrac{4}{7}$

$x=\dfrac{2}{5}-\dfrac{-4}{7}$

$x=\dfrac{34}{35}$

b) $\left(\dfrac{3}{8}-\dfrac{1}{5}\right)+\left(\dfrac{5}{8}-x\right)=\dfrac{1}{5}$

$\dfrac{5}{8}-x=\dfrac{1}{5}-\dfrac{3}{8}+\dfrac{1}{5}$

$\dfrac{5}{8}-x=\dfrac{2}{5}-\dfrac{3}{8}$

$x=\dfrac{5}{8}-\dfrac{2}{5}+\dfrac{3}{8}$

$x=1-\dfrac{2}{5}=\dfrac{3}{5}$Câu trả lời: $-\dfrac{4}{7}-x=\dfrac{3}{5}-2x$