tolong bantu no 1 - 6

2. 2n²-1
= 2.1²-1
= 2.1-1
= 1-1
= 0
2n²-1
= 2.2²-1
= 2.4-1
= 8-1
= 7
2n²-1
= 2.3²-1
= 2.9-1
= 18-1
= 17
#0,7,17
3. 24,34
4. b=6
a=7
n=80
Un = a+(n-1)b
U80 = 7+(80-1)6
= 7+79×6
= 7+474
= 481
5. 15,21,28,36,45,55
6. r = 64/128 = -2
a = 128
n = 10
Un = a.r pangkat n-1
U10 = 128.-2 pangkat 10-1
= 128.-2 pangkat 9
= 128.1024
= 131072