Решите уравнение 1)|x| + 3 = 8 2)|x| - 1,3 = 1,2 3)|x| - 0,8 = - 0,1 4)|x| + 2,1 = 1...

Question

Решите уравнение
1)|x| + 3 = 8
2)|x| - 1,3 = 1,2
3)|x| - 0,8 = - 0,1
4)|x| + 2,1 = 1
5)13 - |x| = 6
6)|x + 2,1| =3

Answer 1

1) [x] = 8 - 3 = 5, x = -5; x = 5.
2) [x] = 1.2 + 1.3 = 2.5; x = +- 2.5
3) [x] = 0.8 - 0.1 = 0.7; x = +- 0.7.
4) [x] = 1 - 2.1 = -1.1    Не может быь, т.к.  [x] >= 0.
5) [x] = 13 - 6; x = +- 7.
6) x + 2.1 = 3, & x + 2.1 = - 3. => x = 0.9 & x = - 5.1.