原式可化为lg[(x^2+4x-26)/(x-3)]=lg10
可化为(x^2+4x-26)/(x-3)=10
x^2+4x-26=10(X-3)
X^2-6X+4=0
(X-3)^2=5
X=3±√5
方程lg(x^2+4x-26)-lg(x-3)=1的解为
原式可化为lg[(x^2+4x-26)/(x-3)]=lg10
可化为(x^2+4x-26)/(x-3)=10
x^2+4x-26=10(X-3)
X^2-6X+4=0
(X-3)^2=5
X=3±√5