Question

va rog este urgent dau coroana +20 de puncte
3)rezolvati in Z inecuatiile
a)x+4<sau egal -3
b)-2x+1>sau egal -3x+4-5x
c)-5x+6<-4
d)3x+5<sau egal 4x+2
e) 3(x+4)-5>2(x+1)

4)determinati numerele naturale intregi negative, mai mari decat -5 , care verifica inegalitatile
a) 3x-2> sau egal 5x-4
b) |x+1|< sau egal 4. (acest semn | insemna modulul unui nr)

5) este o poza
6)aflati z si y numere intregi pentru care xy+2x-3y=16

Answer 1

3)

x+4≤-3

x≤-3-4

x≤-7

3x+5≤4x+2

5≤4x+2-3x

5≤x+2

5-2≤x

3<x

x≥3

3(x+4)-5>2(x+1)

3x+12-5>2x+2

3x+7-2x>2

x+7>2

x>2-7

x>5

4)

3x-2≥5x-4

-2≥5x-4-3x

-2≥2x-4

-2+4≥2x

2>2x

1≥x

x≤1

|x+1|≤4

-4≤x+1≤4

-4-1≤x≤4-1

-5≤x≤3

5)

-3(x-5)-4=5-3(x+5)

-3x+15-4=5-3x-15

-3x+11=5-3x-11

-3x+11=-3x-10

11=-10

||-2+x|-15|=|2²-5¹|

||x-2|-15|=|4-5|=|-1|=1

(x-2)-15=1

-(-(x-2)-15)=1

x-2-15=1

x-17=1

x=1+17=18

x-2+15=1

x+13=1

x=1-13=-12