SOLUTION: Solve for R: 1/R = 1/A + 1/B I thought I had this worked out, but was not sure I could do what I did. I multipled both sides of the equation by 1/1 which allowed me to end u

Algebra ->  Expressions -> SOLUTION: Solve for R: 1/R = 1/A + 1/B I thought I had this worked out, but was not sure I could do what I did. I multipled both sides of the equation by 1/1 which allowed me to end u      Log On


   

Question 43382: Solve for R:
1/R = 1/A + 1/B
I thought I had this worked out, but was not sure I could do what I did. I multipled both sides of the equation by 1/1 which allowed me to end up with R = A + B. Can this be correct? What did I do wrong?
John
Answer by psbhowmick(878) About Me  (Show Source):
You can put this solution on YOUR website!
1%2FR+=+1%2FA+%2B+1%2FB
or 1%2FR+=+%28A+%2B+B%29%2F%28A%2AB%29
or R+=+A%2AB%2F%28A+%2B+B%29

So you are wrong!

You must note that 1%2FA+%2B+1%2FB and 1%2F%28A+%2B+B%29 are not the same. Here you committed the mistake.