Question

Giải các phương trình sau 

a, \(\sqrt{x^2-x}=\sqrt{3-x}\)

b, \(\sqrt{x^2-x-6}=\sqrt{x-3}\)

c, \(\sqrt{x^2+x}=x\)

Answer 1

Answer 2

a)\(\Leftrightarrow x^2-x=3-x\)

\(\Leftrightarrow x^2=3\Leftrightarrow x=\pm\sqrt{3}\)

Answer 3

b)\(\Leftrightarrow x^2-x-6=x-3\Leftrightarrow x^2-2x-3=0\Leftrightarrow\left(x-3\right)\left(x+1\right)\)

\(\Leftrightarrow\)\(\left[\begin{array}{nghiempt}x-3=0\\x+1=0\end{array}\right.\)\(\Leftrightarrow\)\(\left[\begin{array}{nghiempt}x=3\\x=-1\end{array}\right.\)

Answer 4

c)\(\Leftrightarrow x^2+x=x^2\Leftrightarrow x=1\)