Question

help~in x + in (x = 3) = in 10

Answer 1

楼主的题目是：lnx+ln(x-3)=ln10吧?

lnx+ln(x-3)=ln10

x>0,x-3>0

x(x-3)=10

x^2-3x-10=0

(x-5)(x+2)=0

所以 x=5, x=-2(舍去）