Question

rezolvați ecuatia 3(x+2√3)^2-5=4​

Answer 1

$3(x+2\sqrt{3})^2-5=4\\3(x^2+2^2\times\sqrt3^2)-5=4\\3(x^2+4\times3)-5=3\\3(x^2+12)-5=3\\3x^2+36-5=3\\3x^2+31=3\\3x^2=3-31\\3x^2=-27\\x^2=-27:3\\x^2=-9\\x=\pm\sqrt9\\\bf\red{x_1=+3}\\\red{x_2=-3}$