Question

A ={x apartine N/10 se divide cu (x-2)}
B ={x apartine N/(2x+1) apartine D15(D indice 15)
C ={x apartine N/(2x-1) apratine D25
D ={x apartine N/(3x-1) apartine D33
E ={x apartine N /(2x+1) apartine D14
F ={x apartine N /(x+5) apartine D28
G ={x apartine N/(x-3) apartine D12

Answer 1

x-2 ∈ D10
x-2 ∈ {1,2,5,10}
x∈{3,5,7,12} ⇒ A= {3,5,7,12}

2x+1 ∈{1,3,5,15}
2x∈{0,2,4,14}
x∈{0,1,2,7} ⇒ B={0,1,2,7}

2x-1 ∈{1,5,25}
2x ∈{2,6,26}
x∈{1,3,13} ⇒ C={1,3,13}

3x-1∈{1,3,11,33}
3x∈{2,4,12,34}
singurul nr natural care se imparte la 3 este 12
x∈ {4} ⇒ D = {4}

2x+1∈{1,2,7,14}
2x∈{0,1,6,13}
doar nr 0 si 6 se impart la 2
E={0,3}

x+5∈{1,2,4,7,14,28}
x trebuie sa fie nr natural deci x> 5
x∈{2,9,23}  ⇒ F={2,9,23}

x-3 ∈{1,2,3,4,6,12}
x∈{4,5,6,7,9,15} ⇒ G={4,5,6,7,9,15}