Resistor Equation Process

Question

The resistor equation is 1/R=1/r₁ + 1/r_2.

Which of the following is the best first step to use in order to isolate r_2?

 

1. Add or subtract to isolate the term for which you are solving.

2. Multiply by coefficients to eliminate parentheses.

3. Multiply through to eliminate all denominators. 

4. Multiply or divide to isolate the variable you are solving for.

5. None of the above

 

Answer 1

3.

 

1/R=1/r₁+1/r₂

multiply both sides by Rr₁r₂ to get r₁r₂=Rr₂+Rr₁, now you can isolate r₂ using properties of equality and the distributive property