How many values of satisfy the equation above?
Notations:
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∣ 2 x − 1 ∣ = 3 ⌊ x ⌋ + 2 { x }
Since:
x = ⌊ x ⌋ + { x }
Therefore:
∣ 2 x − 1 ∣ = 3 ⌊ x ⌋ + 2 { x } ⟺ ∣ 2 x − 1 ∣ = 2 x + ⌊ x ⌋
Now, we have two cases:
1.) 2 x − 1 ≥ 0 ⟺ x ≥ 0 . 5
2 x − 1 = 2 x + ⌊ x ⌋
− 1 = ⌊ x ⌋
− 1 ≤ x < 0
However, since x ≥ 0.5 we don't have any solutions in this case.
2.) 2 x − 1 < 0 ⟺ x < 0 . 5
1 − 2 x = 2 x + ⌊ x ⌋
1 = 4 x + ⌊ x ⌋
If x is negative, then it's floor is also negative, so we would have a negative number on the RHS, which cannot be equal the positive LHS, so no solution here.
If 0 ≤ x < 0.5 , then:
⌊ x ⌋ = 0
Therefore:
1 = 4x
x = 0.25
This means, that we only have one solution (x = 0.25).
Hence, our answer should be: 1