Answer:
y = 4(3)^x
Step-by-step explanation:
Here, we want to write the exponential equation
From the question, we have the equation tripling in x value every year and the original amount is 4
The exponential equation is of the form;
y = a(b)^n
In this case;
a = 4 , b = 3 and n = x
So we have the equation as;
y = 4(3)^x