X^2+3X=18 ПОМОГИТЕ РЕШИТЬ

Question

X^2+3X=18 ПОМОГИТЕ РЕШИТЬ

Answer 1

X² + 3x = 18
x² + 3x - 18 = 0
D = b² - 4ac = 3² - 4 × 1 × ( - 18) = 9 + 72 = 81 = 9²
x₁ = - 3 +9 / 2 = 6 / 2 = 3
x₂ = - 3 - 9 / 2 = - 12 / 2 = - 6