Question

2 ) Giai pt :

a ) \(\sqrt{9x^2}=2x+1\)

b ) \(\sqrt{x^2+6x}+9=3x-1\)

Answer 1

b sai \(\sqrt{x^2+6x+9}\) ms đúng

Answer 2

a)\(\sqrt{9x^2}=2x+1\)

\(\Leftrightarrow\sqrt{\left(3x\right)^2}=2x+1\) 

<=>3|x|=2x+1

dễ r`

 

 

 

Answer 3

Câu a dễ r câu b nha

Answer 4

b)\(\sqrt{x^2+6x+9}=3x-1\)

\(\Leftrightarrow\sqrt{\left(x+3\right)^2}=3x-1\)

\(\Leftrightarrow x+3=3x-1\)

\(\Leftrightarrow-2x=-4\)

\(\Leftrightarrow x=2\)