Question

log10 (x-1)+ log10 (x+1)=log102. помогите решить​

Answer 1

$log_{10}(x-1)+log_{10}(x+1)=log_{10}2; ; ,; ; ; ODZ:; left { {{x-1>; 0} atop {x+1>0}} right. ; ,; ; x>1\\lg(x^2-1)=lg2\\x^2-1=2\\x^2-3=0\\(x-sqrt3)(x+sqrt3)=0\\x_1=-sqrt3<1; ,; ; x_2=sqrt3in ODZ\\Otvet:; ; x=sqrt3; .$