Answer:
[tex]\Huge \boxed{K=39}[/tex]
Step-by-step explanation:
To solve this problem, first you have to isolate it on one side of the equation. Addition property of equality is adding both sides of an equation the same number doesn't change the equation.
First, add 30 from both sides.
[tex]\displaystyle -30+k+30=9+30[/tex]
Solve.
[tex]\displaystyle 9+30=\boxed{39}[/tex]
In conclusion, the correct answer is [tex]\boxed{k=39}[/tex].
