rozwiąż równania kwadratowe . (z Δ) a) x² - 9x - 22 = 0 b) x² - x - 30 = 0 c) (x-1)(x-2) = 20 Pilne.! Dam NAJ.!

a) x² - 9x - 22 = 0 Δ = 81 + 88 = 169 √Δ = √169 = 13 x = (9 - 13)/2 lub x = (9 + 13)/2 x = - 2 lub x = 11 b) x² - x - 30 = 0 Δ = 1 + 120 = 121 √Δ = √112 = 11 x = (1 - 11)/2 lub x = (1 + 11)/2 x = - 5 lub x = 6 c) (x-1)(x-2) = 20 x² - 2x - x + 2 - 20 = 0 x² - 3x - 18 = 0 Δ = 9 + 72 = 81 √Δ = √81 = 9 x = (2 - 9)/2 lub x = (2 + 9)/2 x = - 3,5 lub x = 5,5

a) x²-9x-22=0 Δ=b²-4ac Δ=81+88 Δ=169 => √Δ=13 ........-b-√Δ x₁ = _______=9-13/2,(w takim zapisie wszedzie tu jest 2 w mianowniku)=-2 ;.........2a ........-b+√Δ x₂ = _______=9+13/2<-w mian.=11 ;.........2a ____________________________________________________________ b) x² - x - 30 = 0 Δ=b²-4ac Δ=121 => √Δ=11 ........-b-√Δ x₁ = _______=-1-11/2,-w mian. =-6 ;.........2a ........-b+√Δ x₂ = _______=1-11/2<-w mian.=5 ;.........2a ___________________________________________________________ c) (x-1)(x-2) = 20