\(\dfrac{5}{7}x-x=\dfrac{8}{7}\)
Bài làm
Ta có:
\(\Rightarrow\dfrac{5}{7}x-x.1=\dfrac{8}{7}\)
\(\Rightarrow(\dfrac{5}{7}-1).x=\dfrac{8}{7}\)
\(\Rightarrow-\dfrac{2}{7}.x=\dfrac{8}{7}\)
\(\Rightarrow x=\dfrac{8}{7}:-\dfrac{2}{7}\)
\(\Rightarrow x=\dfrac{8}{7}.-\dfrac{7}{2}\)
\(\Rightarrow x=-\dfrac{56}{14}=-4\)
\(Vậy\) x = -4
\(\dfrac{5}{7}x-x=\dfrac{8}{7}\)
\(\dfrac{5}{7}x-1.x=\dfrac{8}{7}\)
\(\Rightarrow x\left(\dfrac{5}{7}+1\right)=\dfrac{8}{7}\)
\(\Rightarrow x\left(\dfrac{12}{7}\right)=\dfrac{8}{7}\)
\(x=\dfrac{8}{7}\div\dfrac{12}{7}=\dfrac{8}{7}.\dfrac{7}{12}\)
\(x=\dfrac{2}{3}\)
bn tự vậy nhé !!!
~ chúc bn học tốt ~
