Question 437708
ln(x^2) = ln(20-x) 
Same as
x^2 = 20-x
x^2 + x - 20 = 0
factors to
(x+5)(x-4) = 0 
two solutions
x = -5
and
x = +4
:
:
Check x=-5 with a calc: 
enter: ln((-5)^2) = 3.22
enter: ln(20-(-5)) = 3.22
:
Do the same with x=4