Berikan rumus suku ke-n dari barisan 1). -1/2, 2/3, -3/4, 4/5,.... 2). 1, 4, 9, 16, ...

1.) Diket a=-½, b=
[tex] \frac{2}{3} - ( - \frac{1}{2} ) = \frac{7}{6} [/tex]
Un=a+b(n-1)
=-½+7/6(n-1)
=-½+7/6n-7/6
=
[tex] \frac{7}{6} n - \frac{7}{6} - \frac{1}{2} = \frac{7}{6} n - \frac{10}{6} [/tex]
2.) Diket a=1, b=4-1=3
Un=a+b(n-1)
=1+3(n-1)
=1+3n-3
=3n-3+1
=3n-2