Question 970639
first of all, is that a natural log (base 10) ? the way you write makes me confuse...  if yes, 
log (1/5) [(x^2+x)-(x^2-x)] = -1
log (1/5) [x^4-x^2] = -1
10^(-1) = (1/5)( x^4-x^2)
1/10 = (1/5) (x^4-x^2)
1/2 = (x^4-x^2)
x = -1.169 (2 multiplicity)
x = 1.169 (2 multiplicity)