Question

(X+5) . (X-2) + (2X-1) . (X+1)​

Answer 1

(x+5).(x-2)+(2x-1).(x+1)

X²-2x+5x-10+2x²+2x-1x+1

3x²+4x-9=0

Answer 2

$(x + 5) \times (x - 2) + (2x - 1) \times (x + 1) \\ = x {}^{2} - 2x + 5x - 10 + 2x {}^{2} + 2x - x - 1 \\ = 3 {x}^{2} + 4x - 11 \\ 3x {}^{2} + 4x - 11 = 0$

usando a fórmula de delta agora

$delta = b {}^{2} - 4ac \\ = 4 {}^{2} - 4(3)( - 11) \\ = 16 + 132 \\ delta = 148$

usando a fórmula de bhaskara agora

$- b + - \frac{ \sqrt{ b {}^{2} - 4ac } }{2a}$

$\frac{ - 4 + 12}{6} \\ x1 = \frac{8}{6}= \frac{4}{3} \\ \\ \\ \frac{ - 4 - 12}{6} \\ x2 = \frac{ -16}{6}= \frac{-8}{3}$