Zad. 1
a) Odp. Czwarty wyraz
[tex]5=4n-11\\4n=16\\n=4[/tex]
b) Odp. Trzeci wyraz
[tex]5 = n^{2} -2n+2\\n^{2} -2n+2-5=0\\ n^{2} -2n-3=0\\\\\Delta = b^{2} -4ac = (-2)^{2} -4*1*(-3)=4+12 = 16\\\sqrt{\Delta }=4\\\\n_{1} =\frac{-b-\sqrt{\Delta} }{2a} =\frac{2-4}{2} < 0\\n_{2} =\frac{-b+\sqrt{\Delta} }{2a}=\frac{2+4}{2}=3[/tex]
Zad. 2
[tex]\frac{8}{3} =\frac{3n}{n+1} \\8*(n+1) = 3*3n\\8n + 8 = 9n\\n = 8[/tex]
Odp. Ósmy wyraz
