С МАТЕМАТИКОЙ 5) J7х + 9 = 2х – 1, 969. Решите системы неравенств (969, 970): 1) (2x + 7 > 1, 3) [4.x +9 > -15, Ix-3< 1; 2-х < 5; | 4+11x > 9x – 14, х х 6) x > 0, 2) (3y < 21, |4-у > 0; 4) (2x + 3 > x-1, 5х – 22 < x+2; x – 5> 2x +1. - - С ЧЕРТЕЖОМ

1)

{2x+7 >1

{x - 3<1

{2x > 1 - 7

{x < 1 + 3

{x > (- 6)/2

{x < 4

{ x> - 3

{ x< 4

x∈ (-3;4)

2)

{3y<21

{4-y>0

{y < 21/3

{4 > y

{y<7

{y< 4

y∈(-∞,4 )

3)

{4х +9 > -15

{2-x<5

{4x> -15 -9

{2-5 < x

{4x > -24

{x >-3

{x>-24/4

{x>-3

{x>-6

{x>-3

x∈(-3; ∞ )

4)

{2x+3>x-1

{5x-22<x+2

{2x -x > -1-3

{5x-x< 2+22

{x>-4

{4x<24

{x>-4

{x<6

x∈(-4 , 6 )

5)

{7x+9<2x-1

{4+11x>9x-14

{7x-2x<-1-9

{11x-9x>-14-4

{5x<-10

{2x> - 18

{x<-2        

{x> - 9

x∈ (-9, - 2)

6)

{x>0

{x-5>2x+1           ⇒  -5-1>2x-x  

{x>0

{x< -6

х ∈ ∅   нет решении