Question

DAU 45 DE PUNCTE URGENT!!

3. Descopera si corecteaza greseala:
f) { x | x este ultima cifra a puterilor lui 3} ⊆ {1,3,7,9}
g) { x ∈ N | 6 ⋮ x } ⊃ {x ∈ N | 3 ⋮ x}
h) {3n | n ∈ N} ⊂ {0,3,6,9,12}
i} {x | x ∈ N , x < 4} ⊂ {1,2,3}
j {n | 2" = 1} ⊂ {0,1}
k {x ∈ N | x · 2 = 6 } ⊂ {1,2,3}
l} {x ∈ N | 2x + 1 ≤ 3} ⊆ {0,1}
m) {x ∈ N | 3x - 2 = 1 } ⊆ {2x-1 < 3}

Answer 1

Cele la care nu am scris "adevărat" sunt corectate.

3.

f) Adevărat.

g) {x ∈ ℕ | 6 ⋮ x} ⊂ {x ∈ ℕ | 3 ⋮ x}

h) {3n | n ∈ ℕ} ⊃ {0,3,6,9,12}

i) {x | x ∈ ℕ , x < 4} ⊃ {1,2,3}

j) {n | 2ⁿ  = 1} ⊂ {0,1}

k) {x ∈ ℕ | x·2 = 6 } ⊂ {1,2,3}  (Adevărat)

l) {x ∈ ℕ | 2x + 1 ≤ 3} ⊆ {0,1}  (Adevărat)

m) {x ∈ ℕ | 3x - 2 = 1 } ⊇ {2x - 1 < 3}

3x - 2 = 1 ⇔ 3x = 3 ⇔ x = 1

2x - 1 < 3 ⇔ 2x < 4 ⇔ x < 2