Question

[Quoc Tran Anh Le]

Tìm x, biết:

a) |x| = 4;         b) |x| = \(\sqrt 7 \);      c) |x+5| = 0;     d) \(\left| {x - \sqrt 2 } \right|\) = 0

Answer 1

[Hà Quang Minh]

a) |x| = 4

\(\left[ {_{x =  - 4}^{x = 4}} \right.\)

Vậy \(x \in \{ 4; - 4\} \)

b) |x| = \(\sqrt 7 \)

\(\left[ {_{x =  - \sqrt 7 }^{x = \sqrt 7 }} \right.\)

Vậy \(x \in \{ \sqrt 7 ; - \sqrt 7 \} \)

c) ) |x+5| = 0

x+5 = 0

x = -5

Vậy x = -5

d) \(\left| {x - \sqrt 2 } \right|\) = 0

x - \(\sqrt 2 \) = 0

x = \(\sqrt 2 \)

Vậy x =\(\sqrt 2 \)