(2x+1)/(x+3) -(x-1)/(x²-9) = (x+3)/(3-x) - (4+x)/(3+x) D: x²-9≠0 x²≠9 x≠3 x≠-3 (2x+1)/(x+3) -(x-1)/(x²-9) = (x+3)/(3-x) - (4+x)/(3+x) /*(x-3)(x+3) (2x+1)(x-3)-(x-1)=-(x+3)(x+3)-(x+4)(x-3) 2x²-6x+x-3-x+1=-x²-6x-9-x²+3x-4x+12 2x²+x²+x²-6x+7x-2-3=0 4x²+x-5=0 Δ=1-4*4*(-5)=1+80=81 √Δ=9 x₁=(-1-9)/8=-10/8=-5/4 x₂=(-1+9)/8=8/8=1 Odp. x₁=-5/4 v x₂=1
rozwiązanie w załączniku
[(2x+1)/(x+3)] - [(x-1)/(x²-9)] = [(x+3)/(3-x)] - [(4+x)/(3+x)] Wyznaczmy najpierw dziedzinę funkcji: x²-9≠0 x²≠9 x≠3 x≠-3 x∈R - {-3}; {3} (2x+1)/(x+3) -(x-1)/(x²-9) = (x+3)/(3-x) - (4+x)/(3+x) |*(x-3)(x+3) (2x+1)(x-3)-(x-1)=-(x+3)(x+3)-(x+4)(x-3) 2x²-6x+x-3-x+1=-x²-6x-9-x²+3x-4x+12 2x²+x²+x²-6x+7x-2-3=0 4x²+x-5=0 Δ=81 x1=(-1-9)/8=-10/8=-5/4 x2=(-1+9)/8=8/8=1