a,\(\Leftrightarrow\)\(\sqrt{\left(x-3\right)\left(x+3\right)}+\sqrt{\left(x-3\right)^2}\) \(^2\)\(=0\)
\(\Leftrightarrow\)\(\sqrt{\left(x-3\right)\left(x+3\right)}+x-3=0\)
\(\Leftrightarrow\)\(x=3\)
b, \(\Leftrightarrow\)\(\sqrt{\left(x-1\right)^2}+\sqrt{\left(x-2\right)^2}=3\)
\(\Leftrightarrow\)\(x-1+x-2=3\)
\(\Leftrightarrow\)\(2x=6\)
\(\Leftrightarrow\)\(x=3\)
Nhớ k nhé