Question

Х=-b±b-²4ас
2a
3х²+5x-2=0
2x²-9 x+7=0​

Answer 1

Fórmula General:

Х=-b±b-²4ас/2a

1)

3x^2 + 5x - 2 = 0

a = 3

b = 5

c = -2

$x1 = (- 5 + \sqrt{ {5}^{2} - 4(3)( - 2) } ) \div 2(3)$

$x1 = (- 5 + \sqrt{25 + 24}) \div 6$

$x1 = (- 5 + \sqrt{49}) \div 6$

$x1 = (- 5 + 7 )\div 6$

$x1 = \frac{2}{6}$

$x1 = \frac{1}{3}$

$x2 = \frac{( - 5 - 7)}{6}$

$x2 = \frac{ - 12}{6}$

$x2 = - 2$

2)

2x^2 - 9x + 7 = 0

a = 2

b= -9

c = 7

$x1 = - ( - 9) + \sqrt{ {( - 9)}^{2} - 4(2)(7)} \div 2(2)$

$x1 = 9 + \sqrt{81 - 42} \div 4$

$x1 = 9 + \sqrt{39} \div 4$

$x1 = \frac{9}{4} + \frac{ \sqrt{39} }{4}$

$x2 = \frac{9 - \sqrt{39} }{4}$

$x2 = \frac{9}{4} - \frac{ \sqrt{39} }{4}$