\(\left(x-7\right)^2-x\left(x-9\right)=14\)
\(\Leftrightarrow x^2-14x+49-x^2+9x=14\)
\(\Leftrightarrow-5x=-35\)
<=> x = 7
\(\left(x-7\right)^2-x\left(x-9\right)=14\)
\(\Leftrightarrow x^2-14x+49-x^2+9x=14\)
\(\Leftrightarrow49-5x=14\)
\(\Leftrightarrow5x=49-14\)
\(\Leftrightarrow5x=35\)
\(\Leftrightarrow x=35:5\)
\(\Leftrightarrow x=7\)
\(\left(x-7\right)^2-x\left(x-9\right)=14\)
\(\Leftrightarrow x^2-14x+49-x^2+9x=14\)
\(\Leftrightarrow-5x+49=14\)
\(\Leftrightarrow5x=35\)
=> x =7
Vậy x=7
