Question

a) 4x² - 19X - 5 = 0
b) 2x² + 5x – 3 = 0
Resolva e explique:

(ajuda prfvr!)​

Answer 1

Resposta:

Utilizando o teorema de Bhaskara, encontramos as raízes que tornam a equação verdadeira:

a) 4x² - 19X - 5 = 0

a = 4

b = -19

c = -5

$x = \frac{-(b) +- \sqrt{(b)^{2} - 4 * a * c} }{2*a}$

$x = \frac{-(-19) +- \sqrt{(-19)^{2} - 4 * 4 * -5} }{2*4}$

$x = \frac{19+-\sqrt{361+80} }{8}$

$x = \frac{19+-\sqrt{+441} }{8}$

$x = \frac{19+-21}{8}$

$x' = \frac{19+21}{8}= \frac{40}{8}= 5$

$x'' = \frac{19-21}{8}= \frac{-2}{8}=\frac{-1}{4}$

b) 2x² + 5x – 3 = 0

a = 2

b = 5

c = -3

$x = \frac{-(b) +- \sqrt{(b)^{2} - 4 * a * c} }{2*a}$

$x = \frac{-(5) +- \sqrt{(5)^{2} - 4 * 2 * -3} }{2*2}$

$x = \frac{-5+-\sqrt{25+24} }{4}$

$x = \frac{-5+-\sqrt{+49} }{4}$

$x = \frac{-5+-7}{4}$

$x' = \frac{-5+7}{4}= \frac{2}{4}=\frac{1}{2}$

$x' = \frac{-5-7}{4}= \frac{-12}{4}=-3$