What is the answer to Rt-2n=y for t

In the equation given in the question, there are several unknown variables like t, n, R and y. So a proper solution cannot be reached. Only thing that can be done is, an equation for t can be found.

Rt - 2n = y

Rt = y + 2n

t = (y + 2n) / R

If the value of the other variables in the equation had been given, then the actual value of t could be easily determined. In this case only another equation can be formed as the other variables are unknown

Rt - 2n = y

Add 2n to both sides:

Rt = y + 2n

Divide R to both sides:

t = (y + 2n) / R