Question

-x²+x+12=0 ! PFR ME AJUDEM É PRA HJ

Answer 1

-x² + x + 12 = 0

x² - x - 12 = 0

∆ = b² - 4.a.c ---> a = 1; b = (-1); c = (-12)

∆ = (-1)² - 4.1.(-12)

∆ = 1 + 48

∆ = 49

$x = \frac{ - b ± \sqrt{∆} }{2 \times a}$

$x = \frac{ -( - 1) ± \sqrt{49} }{2 \times 1}$

$x = \frac{1 ± 7}{2}$

$x' = \frac{1 + 7}{2} \\ x" = \frac{1 - 7}{2}$

x' = 8/2 ; x" = -6/2

$x' = 4 \\ x" = - 3$