Question

resolver as equacoes abaixo:

com conta se possivel

Answer 1

$a)\\log_{_x}144=2\\\\144=x^2\\\\12^2=x^2\\\\x=12\\\\\\b)\\log\,(x-4)=0\\\\(x-4)=10^0\\\\x-4=1\\\\x=1+4\\\\x=5\\\\\\c)\\log_{_4}x^2+3x=log_{_4}40\\\\x^2+3x=40\\\\x^2+3x-40=0\\\\Bhaskara\\\Delta=3^2-4.1.(-40)\\\Delta=9+160\\\Delta=169\\\\x_1=\frac{-3+\sqrt{169}}{2}=\frac{-3+13}{2}=5\\\\x_2=\frac{-3-\sqrt{169}}{2}=\frac{-3-13}{2}=-8$