The equation
E=VIT
On the left hand side there is only one variable i.e. E. On the right hand side there are three variables that are all multiplying with each other i.e. VIT. Now to make V subject of the formula use the basic mathematics techniques.
E/IT=V
OR
V=E/IT
This is the final answer where we have made V to be the subject of the formula. Now if we have values for E,I and T we can get the value for V just by inserting the values in the above formula