Answer:
All real numbers
Step-by-step explanation:
Set up the problems 15k+9 and 3( 2k+3) +9k together like this:
15k+9 = 3( 2k+3) +9k, then solve.
[tex]\mathrm{Expand\:}3\left(2k+3\right)+9k:\quad 15k+9[/tex]
Subtract 9 from both sides: [tex]15k+9-9=15k+9-9[/tex]
Simplify: [tex]15k=15k[/tex], when you divide by 15, you find that you get: [tex]k=k[/tex]
Hope this helps!!