Question

Resolva a equação do 2 grau em IR
3+2x²+5x=0



(calculo completo)

Answer 1

$3+2x^2+5x=0\\\\ a=2;b=5;c=3\\\\\\ \Delta=b^2-4ac\to \Delta=5^2-4*2*3\to \Delta=25-24\to \Delta=1\\\\ x' \neq x''\\\\\\ x= \frac{-b\pm \sqrt{\Delta} }{2a} \to x= \frac{-5\pm \sqrt{1} }{2*2} \to x= \frac{-5\pm 1 }{4} \to \\\\\\ x'= \frac{-5+ 1 }{4} \to x'= \frac{-4 }{4} \to x'=-1\\\\\\ x''= \frac{-5-1 }{4} \to x''= \frac{-6 }{4} \to x= -\frac{3 }{2} \\\\\\\\ S=(-\frac{3 }{2};-1)$