Question

alguém me ajuda por favor dou excelente e sigo quem responder certo, pfvr me ajudem​

Answer 1

$x^{2} -20x - 2\\19 = x^{2} - 20x -2\\\\0 =x^{2} -20x-2-19= b^{2} -4 . a . c\\= (-20)^{2} -4.1.(-21)\\=400 + 84\\= 484\\\\\\x = \frac{-b +- \sqrt{delta} }{2.a} \\x= \frac{20 +ou- 22 }{2} \\x'= (20+22)/ 2 \\x' =21\\\\x" = (20-22)/ 2\\x" -1$