=>(2,8x-50):2/3=51
=>2,8x-50=34
=>2,8x=84
=>x=84/2,8=30
\(\left[2\dfrac{4}{5}x-50\right]:\dfrac{2}{3}=51\)
\(\left(\dfrac{14}{5}x-50\right)=\dfrac{10}{3}\)
\(\dfrac{14}{5}x=\dfrac{160}{3}\)
\(\Rightarrow x=\dfrac{160}{3}:\dfrac{14}{5}\)
\(\Rightarrow x=\dfrac{400}{21}\)
Lời giải:
$(2\frac{4}{5}x-50):\frac{2}{3}=51$
$2\frac{4}{5}x-50=51.\frac{2}{3}=34$
$2\frac{4}{5}x=50+34=84$
$x=84:2\frac{4}{5}=30$