How do you solve log(5x-6) = 2log x?

1 Answer
May 21, 2016

x=2 or x=3

Explanation:

Note that
color(white)("XXX") 2log(x)=log(x^2)

So
color(white)("XXX")log(5x-6)=2log(x)
is equivalent to
color(white)("XXX")log(5x-6)=log(x^2)

which implies
color(white)("XXX")5x-6=x^2

color(white)("XXX")x^2-5x+6=0

color(white)("XXX")(x-2)(x-3)=0

So either
color(white)("XXX")(x-2)=0color(white)("XX")rarrcolor(white)("XX")x=2
or
color(white)("XXX")(x-3)=0color(white)("xx")rarrcolor(white)("XX")x=3