Answer:
Solution: each real number
Step-by-step explanation:
[tex]m+3m+6=4m-9+15\qquad\text{combine like terms}\\\\(m+3m)+6=4m+(-9+15)\\\\4m+6=4m+6\qquad\text{subtract}\ 4m\ \text{from both sides}\\\\4m-4m+6=4m-4m+6\\\\6=6\qquad\bold{TRUE}\\\\\bold{CONCLUSION:}\ \text{infinitely many solutions}[/tex]
