Ответ:
7*( (m+n)^2 ) ; x₁ = 0 ∨ x₂ = 0 ∨ x₃ = 4 ; a₁ = -1 , a₂ = 9
Объяснение:
7m^2+14mn+7n^2 = 7*(m^2+2mn+n^2) = 7*( (m+n)^2 )
2x^3-8x = 0
2x*(x^2 - 4x) = 0
2x = 0 ∨ x^2 - 4x = 0
x = 0 ∨ x*(x - 4) = 0
x = 0 ∨ x = 0 ∨ x - 4 = 0
x₁ = 0 ∨ x₂ = 0 ∨ x₃ = 4
a^2 - 8a - 9 = 0
D = (-8)^2 - 4*1*(-9) = 64 + 36 = 100
a₁ = (8 - √100) / (2*1) = -2 / 2 = -1
a₂ = (8+ √100) / (2*1) = 18 / 2 = 9