Question

5(x+1)(x-3)=4x^2-8x помогите пожалуйста

Answer 1

5 (x + 1) (x-3) = 4x² - 8x

5 (x² - 3x + x - 3) = 4x² - 8x

5x² - 10x - 15 = 4x² - 8x

5x² - 10x - 4x² + 8x - 15 = 0

x² - 2x - 15 = 0

D = b² - 4ac = 4 + 60 = 64

x₁ = (2 - 8)/2 = -3

x₂ = (2 + 8)/2 = 5