Question 39434
parallel circuit with resistors A and B, then the total resistance is given by R where 


{{{ 1/R = 1/A + 1/B }}}
{{{ 1/R = B/(AB) + A/(AB) }}}
{{{ 1/R = (A+B)/(AB) }}}
{{{ R = (AB)/(A+B) }}}


so, given our info of one resistor being x and the other being (x-12), we get:


{{{ 8 = (x(x-12))/(x+(x-12)) }}}
{{{ 8 = (x^2-12x)/(2x-12) }}}
{{{ 8(2x-12) = x^2-12x }}}
{{{ 16x-96 = x^2-12x }}}
{{{ 0 = x^2-28x+96 }}}
{{{ x^2-28x+96 = 0 }}}
(x-4)(x-24) = 0
so x-4=0 or x-24=0
x=4 or x=24


Now x is not 4 for our resistor problem, since the other resistor would then be 4-12 --> -8. This is physically impossible.


So, the only answer we have is that the resistors are 24 and (24-12) --> 12.


jon.