SOLUTION: Problem is Science and medicine. The combined resistance of two resistors R1 and R2 in a parallel circuit is given by the formula Rt=1 ----------- 1 1 -

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Question 79496: Problem is
Science and medicine. The combined resistance of two resistors R1 and R2 in a
parallel circuit is given by the formula

Rt=1
-----------
1 1
- + -
R1 R2
Needs to be simplified
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!

Problem is 
Science and medicine. The combined resistance 
of two resistors R1 and R2 in a
parallel circuit is given by the formula 

Rt+=+1%2F%281%2FR1+%2B+1%2FR2%29

Write the 1 on top as 1%2F1 to
make everything fractions:

Rt+=+%281%2F1%29%2F%28%281%2FR1+%2B+1%2FR2%29%29

The LCD of all the denominators is R1%2AR2.

Write that as %28R1%2AR2%29%2F1

Multiply top and bottom of right side by that

Rt+=+%28+%28R1%2AR2%29%2F1%29%2F%28%28R1%2AR2%29%2F1%29%281%2F1%29%2F%28%281%2FR1+%2B+1%2FR2%29%29

The top just becomes R1%2AR2

Rt+=+%28R1%2AR2%29%2F%28%28%28R1%2AR2%29%2F1%29%281%2FR1+%2B+1%2FR2%29%29

In the bottom we distribute the %28%28R1%2AR2%29%2F1%29
into the right parentheses:



The R1's cancel in the first term on the bottom and the
R2's cancel in the second term on the bottom, so we end 
up with just

Rt+=+%28R1%2AR2%29%2F%28R2%2BR1%29

You might want to reverse the the terms in the bottom
so they will be in numerical order:

Rt+=+%28R1%2AR2%29%2F%28R1%2BR2%29

which says:

"The total resistance of two resistors in parallel is
the product of their resistances over their sum."

Edwin