hasil dari 3log(2x+5)-3log(x^2+4x+4)=-2

3log (2x +5) -3log (x^2 +4x + 4) = -2.
syarat 1. ==> 2x + 5 >= 0/==> x >= -5/2
syarat 2. ==> x^2 +4x + 4 >= 0
(x + 2)(x + 2)>= 0. ==> (x + 2)^2 >= 0 , maka x € Real.
3log (2x + 5)- 3log ( x^2+4x + 4) = -2
3log { (2x + 5)/(x^2+4x+4) } = 3log 3^-2
(2x + 5 ) = 1/9(x^2 + 4x + 4)
9(2x + 5) = x^2 +4x +4
18x + 45 = x^2 + 4x + 4
x^2 -14x -41 = 0
dengan rumus abc didapat
x1 = 7+3√10 dan x2,= 7-3√3