Question 885126
log_(5) (x) + log_(5) (x+5) = 9 
log_(5) [(x)(x+5)] = 9 
(x)(x+5) = 5^9 
x^2+5x = 1953125 
x^2+5x-1953125 = 0
apply the "quadratic" formula:
x = -b+-sqrt(b^2-4ac)/(2a)
to get:
x = {1395.04, -1400.04}
throw out the negative solution (extraneous) to get
x = 1395.04
.
details of quadratic follows:
*[invoke quadratic "x", 1, 5, -1953125 ]