Question

a) 3x² – 7x + 4 = 0​

Answer 1

$3x² – 7x + 4 = 0 \\ 3 {x}^{2} - 3x - 4x + 4 = 0 \\ 3x \times (x - 1) - 4(x - 1) = 0 \\ (x - 1) \times (3x - 4) = 0 \\ x - 1 = 0 \\ 3x = 0 \\ x = 1 \\ x = \frac{4}{3} \\ x1 = 1 \: \: \: \: \: \: x2 = \frac{4}{3}$

Answer 2

Oie, Td Bom?!

$3x {}^{2} - 7x + 4 = 0$

• Coeficientes:

$a = 3 \: , \: b = - 7 \: , \: c = 4$

• Fórmula resolutiva:

$x = \frac{ - b± \sqrt{b {}^{2} - 4ac } }{2a}$

$x = \frac{ - ( - 7)± \sqrt{( - 7) {}^{2} - 4 \: . \: 3 \: . \: 4} }{2 \: . \: 3}$

$x = \frac{7± \sqrt{49 - 48} }{6}$

$x = \frac{7± \sqrt{1} }{6}$

$x = \frac{7±1}{6}$

• $x = \frac{7 + 1}{6} = \frac{8}{6} = \frac{8 \div 2}{6 \div 2} = \frac{4}{3}$

• $x = \frac{7 - 1}{6} = \frac{6}{6} = 1$

$S = \left \{1 \: , \: \frac{4}{3} \right \}$

Att. Makaveli1996