Question

y=-x^2+2x+8 очень срочно

Answer 1

$y = - {x}^{2} + 2x + 8 \\ d = {b}^{2} - 4ac = 4 + 32 = 36 \\ x1 = \frac{ - b - \sqrt{d} }{2a} = \frac{ - 2 - \sqrt{36} }{ - 2} = 4 \\ x2 = \frac{ - b + \sqrt{d} }{2a} = \frac{ - 2 + \sqrt{36} }{ - 2} = - 2$
Ответ: x1= 4, x2= -2