Rozwiaz rownanie: a) xszescian - 7xkwadrat - 4x + 28=0 b) 2x do szecianu - 18x = 0

a) x³ - 7x² -4x + 28 = 0 x²(x - 7) - 4(x - 7) = 0 (x-7)(x²-4) = 0 (x-7)(x-2)(x+2) = 0 x-7=0 v x-2=0 v x+2 =0 x=7 v x=2 v x=-2 b) 2x³ - 18x =0 2x(x²-9) = 0 2x(x-3)(x+3) = 0 2x = 0 v x-3=0 v x+3 = 0 x=0 v x=3 v x=-3