Question

Ex 3 cele încercuite​

Answer 1

3. b) x+3 ≤ 9
x ≤ 9-3
x ≤ 6
x ∈ ℕ
=> x ∈{6;5;4;3;2;1;0}

c) x+4 < 3
x < 3-4
x < -1
x ∈ ℕ
=> x ∈ ∅

d) x+3 < 4
x < 4-3
x < 1
x ∈ ℕ
=> x ∈ {0}

e) x-1 ≤ 6
x ≤ 6+1
x ≤ 7
x ∈ ℤ
=> x ∈ {7;6;5;4;3;2;1;0;-1;-2;-3….}

f) x-2 < 8
x < 8+2
x < 10
x ∈ ℤ
=> x ∈ {9;8;7;6;5;4;3;2;1;0;-1;-2;-3;-4….}