Răspuns:
Bună,
[tex]E(x) = (x + 2) ^{2} - {(x - 3)}^{2} + {x + 4)}^{2} - (x - 5) ^{2} \\ = {x}^{2} + 4x + 4 - {x}^{2} + 6x - 9 + {x }^{2} + 8x + 16 - x ^{2} + 10x - 25 \\ = 28x - 14[/tex]
[tex]7 - E(x) \leqslant 0 \\ 7 - 28x - 14 \leqslant 0 \\ - 28x \leqslant 7 \\ x \ \geqslant - \frac{1}{4} \\ [/tex]
x∈ [-¼ , +∞)
x ∈
