\(\left(x+5\right)\left(x-5\right)-x\left(x-10\right)=5\)
\(=>x^2-25-x^2+10x=5\)
\(=>10x=30\)
\(=>x=3\)
Đề gì mới đúng nha : \(\left(x-5\right)\left(x+5\right)-x\left(x-10\right)=5\)
Làm :
\(\left(x-5\right)\left(x+5\right)-x\left(x-10\right)=5\)
\(\Leftrightarrow x^2-5^2-x^2+10x=5\)
\(\Leftrightarrow10x-25=5\)
\(\Leftrightarrow10x=30\)
\(\Leftrightarrow x=30:10\)
\(\Leftrightarrow x=3\)