Question

1. Rezolvati ecuatiile:
a)2(x-1)-3(2x-3) > 6-3(x+5)

b)4(x-5) supra -9 > 7- 7- supra -9

c) 2x +1 supra 4 + 5 < x + 2 supra 2

d) x-2 supra 3 + 2 > 2x -3 supra 6

e) (3x-2) x ( 2x-3 ) - (2x-1) x (x-2) + 6 x > (2x - 3 ) la puterea 2.

2. Rezolvati:
| -3 x + 4 | = 3x - 4
7 - 4x = | 4x - 7 |
3. Determinati numerele x apartine multimii R care indeplinesc conditiile:
a) - 15 < 2x + 3 < -3
b) 16 < 1 - x < 19

Answer 1

a)2x-2-6x-9>6-3x-15
2x-6x-3x>6+9+2-15
-7x>2
- x>2/7
x<-2/7
b)
(4x-20)/-9>(7-7)/-9
(4x-20)/9>0
4x/9>20/9
4x>20
x>5
c)
(2x+1)/9<(x+2)/2
2x/9-x/2<-1/9+1
(4x-9x)18<8/9
-5x/18<8/9
-5x/2<8
-5x<16
-x<16/5
x>-16/5

d)
(x-2)/5>(2x+3)/6
x/5-2x/6>1/2+2/5
(6x-10x)/30>9/10
-4x/30>9/10
-4x/3>9
-4x>27
x<-27/4

e)
6x^2-9x-4x-6-2x^2+4x+x-2>4x^2-12x+9
4x>15
x>15/4

2.
|3x+4|=3x-4 =0
7-4x=|4x-7| =0 scz nu stiu daca e adevarat .

3.
a) x=-2
b) x=-16 şi -17