Let's see what to do buddy....
_________________________________
Remember from now on ,
rang = output
and also Remember ,
output = y = f(x)
So : range = f(x)
So we must put the range number instead of f(x) and solve for x.
Let's do it...
=======================================


Both sides minus 9


Negatives simplified

Divided both sides by 4


_________________________________







_________________________________







_________________________________







_________________________________







_________________________________







=======================================
So the domain values are :
x = { 2 , 3 , 4 , 6 , 7 , 8 }
_________________________________
And we're done.
Thanks for watching buddy good luck.
♥️♥️♥️♥️♥️