The given equation for electrical current $I$ in a circuit with two resistors in series is:

$I = \frac{V}{R_1 + R_2}$

To solve for $R_2$, follow these steps:

Step 1: Multiply both sides by $R_1 + R_2$

$I(R_1 + R_2) = V$

Step 2: Divide both sides by $I$ to isolate $R_1 + R_2$

$R_1 + R_2 = \frac{V}{I}$

Step 3: Subtract $R_1$ from both sides to solve for $R_2$

$R_2 = \frac{V}{I} - R_1$

Thus, the equation solved for $R_2$ is:

$R_2 = \frac{V}{I} - R_1$

Would you like a more detailed breakdown of these steps or any specific questions answered?

Here are 5 related questions to explore further:

1. How does changing $R_1$ or $R_2$ affect the total current in the circuit?
2. How can you calculate the total resistance in a parallel circuit?
3. What is the relationship between voltage, current, and resistance in Ohm's law?
4. How do you calculate the power dissipated by a resistor in a circuit?
5. What happens to the total resistance when resistors are connected in parallel vs. series?

Tip: Always ensure units are consistent when using formulas involving voltage, current, and resistance. For example, use ohms ($\Omega$) for resistance, volts (V) for voltage, and amperes (A) for current.