P= IRT solve for T To solve for T, you must get T on it's own on one side of the equals sign, with all the other terms on the other side. IRT means that I and R are multiplied by T. To get rid of them we must do the opposite of multiply, which is divide. But because this is an equation, anything we do on one side of the equals sign, must be repeated on the other side. So if we divide the right side by IR, we must also divide the left side by IR