Question

Resolva as equações de 2 grau

3x2-4x+1=0
2x2+3x+1=0
7x2+13x-2=0

Answer 1

Explicação passo-a-passo:

$3 {x}^{2} - 4x + 1 \\ d = ( { - 4)}^{2} - 4 \times 3 \times1 \\ d = 4 \\ x = \frac{ - ( - 4) + - \sqrt{4} }{2 \times 3} \\ x1 = 1 \\ x2 = \frac{1}{3}$

$2 {x}^{2} + 3x + 1 = 0 \\ d = {3}^{2} - 4 \times 2 \times 1 \\ d = 1 \\ x = \frac{ - 3 + - \sqrt{1} }{2 \times 2} \\ x1 = - \frac{1}{2} \\ x2 = - 1$

$7 {x}^{2} + 13x - 2 \\ d = {13}^{2} - 4 \times 7 \times - 2 \\ d = 225 \\ x = \frac{ - 13 + - \sqrt{225} }{2 \times 7} \\ \\ x1 = \frac{ - 13 + 15}{14} = \frac{2}{14} = \frac{1}{7} \\ \\ x2 = \frac{ - 13 - 15}{14} = \frac{ - 28}{14} = - 2$