Question

Resolva o sistema x.y= -180 x+y=3
E urgentr pff me ajudem

Answer 1

$xy = -180 \\ x + y = 3 \\ \\ x +y = 3 \\ x = 3 - y \\ \\ xy = -180 \\ (3 - y)y = -180 \\ 3y - y^2 = -180 \\ -y^2 + 3y + 180 = 0 \\ a = -1, b = 3, c = 180 \\ \\ \Delta = b^2 -4ac \\ \Delta = 3^2 - 4 . (-1) . 180 \\ \Delta = 9 + 720 \\ \Delta = 729 \\ \\ y = \frac{-b \pm \sqrt{\Delta} }{2a} \\ y = \frac{-3 \pm \sqrt{729} }{2 . (-1)} \\ y = \frac{-3 \pm 27}{-2} \\ \\ y = \frac{-3 + 27}{-2} \\ y = \frac{24}{-2} = -12 \\ \\ y = \frac{-3 -27}{-2} \\ y = \frac{-30}{-2} = 15$

$x = 3 - y \\ x = 3 - (-12) = 3 + 12 = 15 \\ x = 3 - 15 = -12$

x = {15, -12}, y = {-12, 15}