Question

ajudem ae pfvr 10x² + 3x - 7 = 0

Answer 1

Resposta:

10x² + 3x -  7  = 0

ax² + bx  +  c = 0

a = 10

b = 3

c = - 7

$x = \dfrac{-\,b\pm \sqrt{b^{2} -\, 4ac } }{2a} = \dfrac{-\,3\pm \sqrt{3^{2} -\, 4\times 10 \times (-\,7)} }{2\times 10}$

$x = \dfrac{-\,3\pm \sqrt{9 + 280} }{20} = \dfrac{-\,3\pm \sqrt{289} }{20} = \dfrac{-\,3\pm \sqrt{289} }{20} = \dfrac{-\,3\pm 17 }{20}$

$x_1 = \dfrac{-\,3 + 17 }{20} = \dfrac{14 }{20} = \dfrac{7 }{10}$

$x_2 = \dfrac{-\,3 -17 }{20} = \dfrac{-\,20 }{20} = -\, 1$