text: simplify the formula. rt=1over 1/r1+1/r2how do i simplify this problem.? the combined resistance of two resistors r1 and r2 in a parallel circuit is given by the formula first: 1/r1 +1/r2 = (r2+r1) / (r1xr2)  rt = inverse of this =  r1xr2/(r1+r2)