x^2+2x+5=0
Let's solve in ℝ: x2 + 2x + 5 = 0
Given the quadratic form ax2 + bx + c, you can calculate the discriminant: Δ = b2 -4ac
Δ = 22 -4·1·5
Δ = 4 -4·5
Δ = 4 -20
Δ = -16
Since Δ < 0, the equation has no solution.
No solution in ℝ for: x
▶Solution:   x ∈ ∅