Question

3. Determinați mulțimile:

C = {x € D10 şi x + 2 € D12};
Repede va rog!!!

Answer 1

C = {x | x ∈ D₁₀ și x+2 ∈ D₁₂}

x+2 ∈ D₁₂ ⇔ x+2 ∈ {-12,-6,-4,-3,-2,-1,1,2,3,4,6,12}

⇔ x ∈ {-14,-8,-6,-5,-4,-3,-1,0,1,2,3,10}

⇒ C = {-10,-5,-2,-1,1,2,5,10} ∩ {-14,-8,-6,-5,-4,-3,-1,0,1,2,3,10}

⇒ C = {-5, 2, 10}