Hope this helped! I’d appreciate brainless answer!
Divide both sides by 5, and the result is: x=30.
X is 30.
4+5 would be 9 because you add 4 and 5
For this case we must find the inverse of the following function:

Then, we follow the steps:
We change
by y:

We exchange the variables:

We clear the variable "y":

We change y for 

Answer:
