Question

Determinati numerele reale x solutii ale inecuatiei 2$x^{2}$ + 2x $\geq$ $x^{2}$ - 2x + 5

Answer 1

2x²+2x >/ x²-2x+5

2x²-x²+2x+2x-5 >/ 0

x²+4x-5 >/ 0

Δ = 16+20 = 36

x₁ = (-4+6)/2 = 2/2 = 1

x₂ = (-4-6)/2 = -10/2 = -5

Deci x = {-5, 1}