HELP...!!! Equation?

0 ⤊

Solve the equation for the indicated variable

1/r + 2/1-r = 4/r^2 ; for r

2007-09-11 15:41:20 · 2 answers · asked by alexo 4 in Science & Mathematics ➔ Mathematics

1/r + 2/1-r =4 /r^2
r^2/r + 2r^2 /1-r = 4
r + 2r^2 - 2r = 4
2r^2 -r =4
2r^2-r -4 =0

2007-09-11 15:49:30 · answer #1 · answered by subash1111 1 · 0⤊ 0⤋

common denominator r^2(1-r)
so r(1-r)+2r^2-4(1-r)=0
r^2 +5r-4=0 so r= ((-5+-sqrt(41)/2

2007-09-11 22:55:26 · answer #2 · answered by santmann2002 7 · 0⤊ 0⤋