Keywords:
<em>Equation, variable, value, clear
</em>
For this case we have an equation with a variable of the form
. Where
. Given the value of
, we want to find the value of the variable "x". So, we have:

We must clear "x", for this, we add "19" to both sides of the equation:

We divide between "3" on both sides of the equation:

Thus, the value of the variable "x" is 30.
Answer:

Option A