Question

Suku ke-n dari : 1. 3,5,7,9,... 2.4,8,12,16,... 3.10,7,4,1,... 4. 3,6,12,24,48,... 5.-2,-4,-8,-16,-32,... 6. 2,1, 1/2, 1/4, 1/8,...

Answer 1

1.) a=3
     b=2
Un=a+(n-1)b
    =3+(n-1)2
    =3n+2n-2
    =1+2n
2.) a=4
     b=4
Un=a+(n-1)b
    =4+(n-1)4
    =4+4n-4
    =4n
3.) a=10
     b=-3
Un=a+(n-1)b
    =10+(n-1)(-3)
    =10+(-3n)(3)
    =13-3n