4. Решите систему уравнений методом сложения: { x + 2y = -5, 3y² – x = 45; 3y² + 2y = 40; 3y² + 2y - 40 = 0; D₁ = 1 + 120 = 121; y₁ = (-1-11)/3 = -4; x₁ = -5 + 8 = 3; y₂ = (-1+11)/3 = 3⅓; x₂ = -5 - 6⅔ = -11⅔.

The provided text seems to be a partial solution to a system of equations, not a complete problem statement. It includes calculations for D₁, y₁, x₁, y₂, and x₂. Without the full problem, a complete solution cannot be provided.