Question

помогите плз дам 20 баллов​

Answer 1

Ответ:

$1) \: x^{2} - 10x + 9 \geqslant 0 \\ d = b^{2} - 4ac \\ d = ( - 10)^{2} - 4 \times 1 \times 9 = 100 - 90 \: d = \sqrt{10} \\ x1.2 = \frac{- b + - \sqrt{d} }{2a} = \frac{ - 10 + - 3.14 }{2} = x1 = - 10 + 3.14 = - 7.86 \: {x}^{2} = - 10 - 3.14 = - 13.14 \\ \\ 12 - 3x < 0 \: \: \div 3 \\ 4 - x = 0 \\ - x = 4 \\ x = - 4 \\ - 4 < 0 \\ \\ 2) \: {2x}^{2} - 5x + 2 > 0 \\ d = {b}^{2} - 4ac \\ d = ( - 5)^{2} - 4 \times 2 \times 2 = 25 - 16 = \sqrt{9} \\ d = \frac{ - b + - \sqrt{d}}{2a} = \frac{- 5 + - 3}{2} \\ x1 = -5 + 3 = - 2 \\ x2 = - 5 - 3 = - 8 \\ \frac{ - 2}{ - 8} = - 4 \\ - 4 > 0 \\ \\ 4x - 1 \geqslant 3 \\ x = - 4 - 1 \\ x = - 5 \\ - 5 \geqslant 3$