task/29445518 ----------------------
1) | x -7 | = 9 ⇔ [ x -7 = - 9 ; x -7 = 9 . ⇔ [ x = -2 ; x = 16.
2 ) | 5+2x | =3 ⇔ [ 2x + 5 = -3 ; 2x + 5 = 3 . ⇔ [ x = - 4 ; x = -1 .
3) 3 +2x = | -2 -3x | ⇔ | 3x +2 | =2x +3.⇔ { 2x +3 ≥ 0 ; [3x +2= -2x-3 ; 3x+2=2x+3
⇔ { x ≥ - 1,5 , [ x = -1 ; x =1 . ⇔ [ x = -1 ; x =1 . * * * x = ± 1 * * *
4) | 2x - 4 | = | x +1 | ⇔ [ 2x - 4= - (x+1) ; 2x - 4= x+1.⇔ [ x = 1 ; x = 5.
5) |x+2| + 3|x - 1|-|x|=6 ⇔ | x+2 | - | x | + 3| x - 1 | = 6 . см еще и приложение
- - - + - - + + - + + +
-------------- -2 ------------ 0 ---------------- 1 --------------
[ { x < -2 ; -x-2 +x -3(x-1) =6 ; { -2 ≤ x < 0 ; x+2 +x -3(x-1) =6 ;
{0 ≤ x < 1 ; x+2 - x -3(x-1) =6 ; { x ≥ 1 ; x+2 - x +3(x-1) =6 . ⇔
[ { x < -2 ; x = -5/3 ; { -2 ≤ x < 0 ; x= -1 ; {0 ≤ x < 1 ; x = - 1/3 ; { x ≥ 1 ; x=7/3 .
ответ : - 1 ; 7/3 .
6) x²+2| x | = 8 ⇔ | x |² +2| x | - 8 =0 ⇔ [ | x | = - 4 ; |x| = 2. ⇔ | x | =2 ⇔ x = ± 2.
task/29445518 ----------------------
1) | x -7 | = 9 ⇔ [ x -7 = - 9 ; x -7 = 9 . ⇔ [ x = -2 ; x = 16.
2 ) | 5+2x | =3 ⇔ [ 2x + 5 = -3 ; 2x + 5 = 3 . ⇔ [ x = - 4 ; x = -1 .
3) 3 +2x = | -2 -3x | ⇔ | 3x +2 | =2x +3.⇔ { 2x +3 ≥ 0 ; [3x +2= -2x-3 ; 3x+2=2x+3
⇔ { x ≥ - 1,5 , [ x = -1 ; x =1 . ⇔ [ x = -1 ; x =1 . * * * x = ± 1 * * *
4) | 2x - 4 | = | x +1 | ⇔ [ 2x - 4= - (x+1) ; 2x - 4= x+1.⇔ [ x = 1 ; x = 5.
5) |x+2| + 3|x - 1|-|x|=6 ⇔ | x+2 | - | x | + 3| x - 1 | = 6 . см еще и приложение
- - - + - - + + - + + +
-------------- -2 ------------ 0 ---------------- 1 --------------
[ { x < -2 ; -x-2 +x -3(x-1) =6 ; { -2 ≤ x < 0 ; x+2 +x -3(x-1) =6 ;
{0 ≤ x < 1 ; x+2 - x -3(x-1) =6 ; { x ≥ 1 ; x+2 - x +3(x-1) =6 . ⇔
[ { x < -2 ; x = -5/3 ; { -2 ≤ x < 0 ; x= -1 ; {0 ≤ x < 1 ; x = - 1/3 ; { x ≥ 1 ; x=7/3 .
ответ : - 1 ; 7/3 .
6) x²+2| x | = 8 ⇔ | x |² +2| x | - 8 =0 ⇔ [ | x | = - 4 ; |x| = 2. ⇔ | x | =2 ⇔ x = ± 2.