Question

2lg(x^2+19)-lg(x+1)=1

Answer 1

lg(x^2+19)^2-lg(x+1)=1
lg  (x^2+19)^2/(x+1)=lg10
lg (x^2+19)^2/(x+1)=lg10
lg (x^2+19)^2 / 10(x+1)=0
 (x^2+19)^2 / 10(x+1)=1
 (x^2+19)^2 = 10(x+1)
 x^4+38x^2-10x+351=0