Question

lg(x-4) + lg(x+3) = lg(5x+4)

Answer 1

{x-4>0⇒x>4
{x+3>0⇒x>-3
{5x+4>0⇒x>-0,8
x∈(4;∞)
lg[(x-4)(x+3)]=lg(5x+4)
(x-4)(x+3)=5x+4
x²+3x-4x-12-5x-4=0
x²-6x-16=0
x1+x2=6 U x1*x2=-16
x1=-2 не удов усл
x2=8