Question

ПОМОГИИИТТЕЕЕЕЕ ПОЖААААЛУУЙЙЙСССТАААА!!!!!СРОЧНОО НУЖНОО​

Answer 1

a)

${9x}^{2} - 4 > 0$

${9x}^{2} - 4 = 0$

$x = \sqrt{ \frac{4}{9} }$

$x = + - \frac{2}{3}$

..+...........-..............+

---(-2/3)-----(2/3)----->

x€(-беск.;-2/3) и (2/3;+беск)

b)

${ - 2x}^{2} + 7x < 0$

${ - 2x}^{2} + 7x = 0$

$x(7 - 2x) = 0$

x=0 или х=3.5

...-..........+...............-

-----(0)-------(3.5)---->

х€(-беск.;0) и (3.5;+беск)

c)

${2x}^{2} + 7x - 4 < 0$

${2x}^{2} + 7x - 4 = 0$

$d = 49 + 32 = 81$

$x1 = \frac{ - 7 + 9}{4} = \frac{1}{2}$

$x2 = \frac{ - 7 - 9}{4} = - 4$

...+.............-...............+

------(-4)-------(1/2)----->

x€(-4;1/2)

d)

${x}^{2} - 30x + 200 > 0$

${x}^{2} - 30x + 200 = 0$

$d = 900 - 800 = 100$

$x1 = \frac{30 + 10}{2} = 20$

$x2 = \frac{30 - 10}{2} = 10$

...+................-...............+

--------(10)-------(20)----->

x€(-беск.;10) и (20;+беск)

e)

${ - 3x}^{2} + 7x \geqslant 5$

${3x}^{2} - 7x + 5 \leqslant 0$

${3x}^{2} - 7x + 5 = 0$

$d = 49 - 60 = - 11$

Решений нет

f)

${25x}^{2} + 10x + 1 \geqslant 0$

${25x}^{2} + 10x + 1 = 0$

$d = 100 - 100 = 0$

$x = \frac{ - 10}{50} = - 0.2$

.......+...............+

--------[-0,2]--------->

x€R