SOLUTION: Please help with solving equation for r : q = rs/(r+s). I tried multiplying by (r+s), but cannot figure out how to get both r's together. Thanks

Algebra ->  Equations -> SOLUTION: Please help with solving equation for r : q = rs/(r+s). I tried multiplying by (r+s), but cannot figure out how to get both r's together. Thanks      Log On


   

Question 163524This question is from textbook Algebra 2 A Teaching Textbook
: Please help with solving equation for r : q = rs/(r+s).
I tried multiplying by (r+s), but cannot figure out how to get both r's together.
Thanks This question is from textbook Algebra 2 A Teaching Textbook

Found 2 solutions by checkley77, ptaylor:
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
q=rs/(r+s)
q(r+s)=rs
qr+qs=rs
qr-rs=-qs
r(q-s)=-qs
r=-qs/(q-s)

Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!
YOU SURE GOT THE FIRST STEP CORRECT!!!!!!
Multiply each side by (r+s) and we get:
q(r+s)=rs get rid of parens (distributive law)
qr+qs=rs subtract qr from each side
qr-qr+qs=rs-qr collect like terms
qs=r(s-q) (distributive law)
divide each side by (s-q)
r=qs/(s-q)--------------------------------ans
CK
q=rs/(r+s)
q=(qs/(s-q))s/((qs/(s-q))+s=
q=(qs^2/(s-q))/(qs+s(s-q))/(s-q)=
q=qs^2/(qs+s^2-qs)=qs^2/s^2
q=q
Hope this helps---ptaylor