Ta có: \(\dfrac{x}{7}-\dfrac{7}{8}=\dfrac{-25}{56}\)
\(\Leftrightarrow\dfrac{x}{7}=\dfrac{-25}{56}+\dfrac{7}{8}=\dfrac{-25+49}{56}=\dfrac{3}{7}\)
hay x=3
Vậy: x=3
\(\dfrac{x}{7}-\dfrac{7}{8}=-\dfrac{25}{56}\)
\(\Rightarrow\dfrac{x}{7}-\dfrac{49}{56}=-\dfrac{25}{56}\)
\(\Rightarrow\dfrac{x}{7}=-\dfrac{25}{56}+\dfrac{49}{56}=\dfrac{3}{7}\)
\(\Rightarrow x=3\)
\(\dfrac{x}{7}-\dfrac{7}{8}=\dfrac{-25}{56}\\ \Rightarrow\dfrac{x}{7}=\dfrac{-25}{56}+\dfrac{7}{8}\\ \Rightarrow\dfrac{x}{7}=\dfrac{24}{56}=\dfrac{3}{7}\\ \Rightarrow x=3\)
Vậy x = 3
\(\dfrac{x}{7}-\dfrac{7}{8}=-\dfrac{25}{56}\)
\(\dfrac{8x}{56}-\dfrac{49}{56}=-\dfrac{25}{56}\)
quy tắc khử mẫu
\(=>8x-49=-25\)
\(8x=-25+49\)
\(8x=24\)
\(x=24:8=3\)
Vậy x=3
\(\dfrac{-25}{56}+\dfrac{7}{8}\)= \(\dfrac{3}{7}\)
=>x=3
\(\dfrac{x}{7}-\dfrac{7}{8}=\dfrac{-25}{56}\)
⇔ \(\dfrac{x}{7}=\dfrac{-25}{56}+\dfrac{7}{8}\)
⇔ \(\dfrac{x}{7}=\dfrac{3}{7}\)
⇒ \(x=3\)
=> \(\dfrac{x}{7}\) = \(\dfrac{-25}{56}\) + \(\dfrac{7}{8}\)
=> \(\dfrac{x}{7}\) = \(\dfrac{3}{7}\)
=> x = 3 (vì có mẫu 7 = 7)
Đây là bài làm của mình nhé
\(\text{Ta có:}\) \(\dfrac{x}{7}-\dfrac{7}{8}\)\(=\)\(\dfrac{-25}{56}\)
⇒\(\dfrac{x}{7}-\dfrac{49}{56}\) \(=\dfrac{-25}{56}\)
⇒ \(\dfrac{x}{7}=\dfrac{-25}{56}+\dfrac{49}{56}=\dfrac{3}{7}\)
⇒\(x=3\)