a) 2x-x²=0 b) ¼x²-4x-1=0 c) -3x²-2x-7=0

a) 2x-x²=0 x(2 - x) = 0 x = 0 lub 2-x = 0 x = 0 lub -x = -2 x = 0 lub x = 2 b) ¼x²-4x-1=0 /4 x² -16x -4 = 0 Δ = (16)² - 4*1*(-4) = 256 + 16 = 272 √Δ= √272 = √16*√17= 4√17 x1 = (4 -4√17): 2*1 = 4( 1-√17): 2 = 2(1-√17) x2 = (4 +4√17): 2*1 = 4( 1+√17): 2 = 2(1+√17) c) -3x²-2x-7=0 Δ = (-2)²-4*(-3)*(-7) = 4 - 84 = -80 Δ < o, więc brak pierwiastków równania