Question

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Imi dau toate punctele!!!!

Answer 1

Răspuns:

a)x^2-5x+4<=0

a=1

b=-5

c=4

Delta=25-16

Delta=9

x

$x =( 5 + \sqrt{9 }) \div 2 = 8 \div 2 = 4$

b)(x-3)(2x-1)>=0

$( \times - 3) \geqslant 0 \\ x = 3$

$2x - 1 \geqslant 0 \\ 2x \geqslant 1 \\ x \geqslant 1 \div 2$

c)x^2-5/x+4>=0

$x { }^{2} - 5 \geqslant 0 \\ x {?}^{2} \geqslant 5$

$x \geqslant \sqrt{5}$

$x + 4 \geqslant 0 \\ x \geqslant - 4$

d)(1/x+1/x-3)<2

$\frac{2}{x(x - 3)} < 2$

$\frac{2}{x {?}^{2} - 3x } \geqslant 2$

2<2x^2+6x

2x^2+6x-2<0

a=2

b=6

c=-2

Delta:36-(-16)=36+16=52

$x = - 6 + \sqrt{52 } \div 4$

e) (x-2)^2*3(x^2-1)=(x^2-4x+4)(3x^2-3)>=6

x^2-4x+4>=6

x^2-4x-2>=0

a=1

b=-4

c=-2

Delta: 16-(-8)=24

$x = (4+ \sqrt{24} ) \div 2 = 4 + 4 \sqrt{3} \div 2$

f) 2x-7/5<=x+1/4

8x-28-5x-5/20<=0

3x-32<=0

3x<=32

x<=32/2

g)x-3/7<x+1/2x

(2x(x-3)-2x(x+1))/2x<=0

(2x^2-6x-2x^2+2x)/2x<=0

-4x/2x<=0

2x<=0

x<=0

h)1/8+x/3-2x+1/5<4/x

5/45+15/45-18x+9/45-180/x/45=(20-18x+9-180/x)/45=(29-18x-180/x)/45=

(29-(18x^2-180)/x)/45=(29x-18x^2-180/x)/45

=(29x-18x^2-180)/45x<0

-18x^2-180-29x<0

a=-18

b=-180

c=-29

Delta=30.312

$x = - 180 + \sqrt{30312} \div 36$