Question

решите неравенство 4 - x < 0
решите уравнение 3x-4x^2=0
x^2+7x+12=0

Answer 1

$4 - x < 0 \\ - x < - 4 \\ x > 4$
Ответ: (4; +беск)


$3x - 4 {x}^{2} = 0 \\ x(3 - 4x) = 0 \\ \\ x = 0 \\ \\ 3 - 4x = 0 \\ 4x = 3 \\ x = \frac{3}{4}$
Ответ: 0; 3/4.

${x}^{2} + 7x + 12 = 0 \\ d = {b}^{2} - 4ac = 49 - 4 \times 12 = 49 - 48 = 1 \\ x1 = \frac{ - b + \sqrt{d} }{2a} = \frac{ - 7 + 1}{2} = - \frac{6}{2} = - 3 \\ x2 = \frac{ - b - \sqrt{d} }{2a} = \frac{ - 7 - 1}{2} = - \frac{8}{2} = - 4$
Ответ: -3; -4.