72-7.(13-x)=14
=>7.(13-x)=72-14
=>7.(13-x)=58
=>13-x=58:7
=>13-x=\(\dfrac{58}{7}\)
\(=>x=13-\dfrac{58}{7}\)
\(=>x=\dfrac{33}{7}\)
Vậy ................
\(72-7(13-x)=14\)
\(7(13-x)=72-14\)
\(7(13-x)=58\)
\(13-x=58:7\)
\(13-x=\) \(\dfrac{58}{7}\)
\(x=13-\dfrac{58}{7}\)
\(x=\dfrac{33}{7}\)
\(72-7\left(13-x\right)=14\)
\(\Rightarrow72-91+7x-14=0\)
\(\Rightarrow7x=33\)
\(\Rightarrow x=\dfrac{33}{7}\)