Answer:-m or m+3
Step-by-step explanation:
[tex]x^{2} -3x -(m^{2}+3m) =0\\\\x^{2} -3x -m^{2} -3m=0\\[/tex]
[tex]x^{2} -m^{2} -3x - 3m=0[/tex]
Applying difference of two squares
⇒([tex]x^{2} -m^{2}[/tex])=(x+m)(x-m)
Substituting this for ([tex]x^{2} -m^{2}[/tex])
Factorising -3x-3m=-3(x+m)
(x+m)(x-m)-3(x+m)=0
since we have double (x+m),we'll pick one
⇒(x+m)=0
or (x-m-3)=0
⇒x=-m or x= m+3
