......................
(-3; 2; -5); (3; -2; 5)
Объяснение:
(x+y)(x+z)=8
(x+y)(y+z)=3
(y+z)(x+z)=24
(x+y)(x+z)(x+y)(y+z)(y+z)(x+z)=8·3·24
(x+y)²(x+z)²(y+z)²=24·24
[(x+y)(x+z)(y+z)]²=24²
(x+y)(x+z)(y+z)=±24
1) (x+y)(x+z)(y+z)=-24
-24=(x+y)(x+z)(y+z)=8(y+z)⇒y+z=-3
-24=(x+y)(x+z)(y+z)=3(x+z)⇒x+z=-8
-24=(x+y)(x+z)(y+z)=24(x+y)⇒x+y=-1
y+z=-3
x+z=-8
x+y=-1
(y+z)+(x+z)+(x+y)=-3+(-8)+(-1)
2(x+y+z)=-12
x+y+z=-6
x=(x+y+z)-(y+z)=-6-(-3)=-3
y=(x+y+z)-(x+z)=-6-(-8)=2
z=(x+y+z)-(x+y)=-6-(-1)=-5
2) (x+y)(x+z)(y+z)=24
24=(x+y)(x+z)(y+z)=8(y+z)⇒y+z=3
24=(x+y)(x+z)(y+z)=3(x+z)⇒x+z=8
24=(x+y)(x+z)(y+z)=24(x+y)⇒x+y=1
y+z=3
x+z=8
x+y=1
(y+z)+(x+z)+(x+y)=3+8+1
2(x+y+z)=12
x+y+z=6
x=(x+y+z)-(y+z)=6-3=3
y=(x+y+z)-(x+z)=6-8=-2
z=(x+y+z)-(x+y)=6-1=5
1. -х*(х+1)>0
x=0; x=-1
__-10
- + -
∈(-∞;-1)∪(0;+∞)
2. (x-4) (x+5)<0
х=4; х=-5
__-54
+ - 5
х∈(-5;4)
3. (2x+7) (1-x)≥0
х=-3.5; х=1
___-3.51
- + -
х∈(-∞;-3.5]∪[1;+∞)