SOLUTION: Solve the formulas below for the indicated variable. Show your work. E/R+r = I, for R Please help me, I don't know how to solve this kind of problem! Thank you!! :)

Algebra ->  Exponents -> SOLUTION: Solve the formulas below for the indicated variable. Show your work. E/R+r = I, for R Please help me, I don't know how to solve this kind of problem! Thank you!! :)      Log On


   

Question 354548: Solve the formulas below for the indicated variable. Show your work.
E/R+r = I, for R
Please help me, I don't know how to solve this kind of problem! Thank you!! :)
Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Sure you do. Let's walk it step by step
E%2FR%2Br+=+I
First thing, you need to make sure the problem is written clearly
Do you mean
%28E%2FR%29%2Br+=+I
or
E%2F%28R%2Br%29+=+I
As written, it is
%28E%2FR%29%2Br+=+I
so let's solve that one
You want to isolate R, so
%28E%2FR%29%2Br+=+I subtract r from each side
%28E%2FR%29+=+I+-+r now multiply both sides by R (assumes R is not zero)
E+=+%28I-r%29+%2A+R now divide both sides by I-r (assumes I-r is not zero)
E%2F%28I-r%29+=+R
there you have it
If the problem was actually
E%2F%28R%2Br%29+=+I
Then do a similar set of steps
E%2F%28R%2Br%29+=+I multiply bith sides by (R+r)
E+=+I+%2A+%28R%2Br%29
E+=+IR+%2B+Ir subrtract Ir from both sides
E+-+Ir+=+IR divide both sides by I
%28E-Ir%29%2FI+=+R
Be careful when posting problems to this site. use as many parens as you need to make the problem clear. Else folks like me can't help much