Question 998769
keep going
5^7=78125
x^2+x-78125=0
quadratic formula, positive root only
x=(1/2)(-1+/- sqrt (1+78125*4); the radical is 559.018
divided by 2, x=279.0089 (do not forget the minus 1 for minus b.  You need it)
log 5(279.0089)=3.4989
log 5 (280.0089)=3.5011  
Those aren't exact, but they are extremely close, and they add to 7.