Question

If V = 12R / (r + R) , then R =

Answer 1

vr+vR=12R
vr=12R-vR
vr=R(12-v)
R=vr/12-v

Answer 2

`V=(12R)/(r+R)\\\\V(r+R)=12R\\\\Vr+VR=12R\\\\VR-12R=-Vr\\\\(V-12)R=-Vr\ \ \ \ /:(V-12)\\eq0\\\\R=(-Vr)/(V-12)\\\\R=(Vr)/(12-V)`