Question

Daca 2xpatrat=72 atunci x apartine?

Answer 1

2x² = 72
x² = 72 : 2
x = √36
x₁ = 6
x₂ = - 6
x ∈ {- 6, 6}

Answer 2

2x² = 72
x² = 72 : 2
x² =36
x=6 sau x=-6
S={ x apartine de la 6 pina la -6}