Question

( 2x - 1)² - ( x + 2)² = -2x
ajuda ainda estou tentando aprender a materia
baskara + delta + conjunto verdade

Answer 1

$( 2x - 1)^2 - ( x + 2)^2 = -2x\to \\\\ 4x^2-4x+1-(x^2+4x+4)+2x=0\to \\\\ 4x^2-4x+1-x^2-4x-4+2x=0\to \\\\3 x^{2} -6x-3=0\\\\ a=3;b=-6;c=-3\\\\\\ \Delta=b^2-4ac\to \Delta=(-6)^2-4*3*(-3)\to \Delta=36+36\to \Delta=72\\\\ x'=x'' \\\\\\ x= \frac{-b\pm \sqrt{\Delta} }{2a} \to x= \frac{-(-6)\pm \sqrt{72} }{2*3} \to x= \frac{6\pm 6\sqrt{2} }{6} \to \\\\\\x'= \frac{6+ 6\sqrt{2} }{6} \to x'= 1+\sqrt{2} \\\\\\ x''= \frac{6-6\sqrt{2} }{6} \to x''= 1-\sqrt{2} \\\\\\\\ S=\{1-\sqrt{2} ;1+\sqrt{2} \}$