Question

me ajudaaaaaaaa pfvrrr​

Answer 1

${3x}^{2} - 2x - 21 = 0$

a = 3

b = -2

c = -21

$∆ = {b}^{2} - 4.a.c \\ ∆ = {( - 2)}^{2} - 4.3.( - 21) \\ ∆ = 4 + 252 \\ ∆ = 256 \\ \\ x = \frac{ - b + - \sqrt{∆} }{2.a} \\ x = \frac{ - ( - 2) + - \sqrt{256} }{2.3} \\ x = \frac{2 + - 16}{6} \\ \\ x1 = \frac{2 + 16}{6} = \frac{18}{6} = 3 \\ \\ x2 = \frac{2 - 16}{6} = \frac{ - 14}{6} \div 2 = \frac{ - 7}{3}$

Espero que tenha ajudado ☺️

Bons estudos ❤️