pliss bgtt yg no 4 dijawabbb

kalau bagi
[tex] log( {x}^{2} + 2x) \div log(3x + 20) \\ \frac{log( {x}^{2} + 2x)}{ log(10) } \div \frac{log(3x + 20) }{ log(10) } \\ \frac{log( {x}^{2} + 2x)}{ log(10) } \times \frac{ log(10) }{log(3x + 20)} \\ = \frac{ log( {x}^{2} + 2x) }{log(3x + 20)} = \frac{ {x}^{2} + 2x }{3x + 20} \\ = \frac{x(x + 2)}{3x + 20} [/tex]

kalau sama dengan
log (x^2 + 2x) = log (3x + 20)
x^2 + 2x = 3x + 20
x^2 - x - 20 = 0
(x - 5) (x + 4) = 0
x = 5 atau x = -4

catatan
^ = pangkat