Write the next term of sequence,and then write the rule for the nth term.

1)1,8,27,64,....125
the nth is

2) 3,8,15, 24,.....35
the nth is

Can you help me and correct ? thank

1 answer

1)

a (n ) = n ^ 3

1 ^ 3 = 1

2 ^ 3 = 8

3 ^ 3 = 27

4 ^ 3 = 64

5 ^ 3 = 125

6 ^ 3 = 216

2 )

a (n ) = n ^ 2 + 2 n

1 ^ 2 + 2 * 1 = 1 + 2 = 3

2 ^ 2 + 2 * 2 = 4 + 4 = 8

3 ^ 2 + 2 * 3 = 9 + 6 = 15

4 ^ 2 + 2 * 4 = 16 + 8 = 24

5 ^ 2 + 2 * 5 = 25 + 10 = 35

6 ^ 2 + 2 * 6 = 36 + 12 = 48