Question

The first five terms of a number sequence are -1, 3, 7, 11, 15. Write down an expression, in terms of n, for the nth term of this sequence

Answer 1

Answer:

here,

a1 = -1

a2 = 3

d = a2 - a1

so, d = 3-(-1)

d = 3 + 1

d = 4

an = 15

so,

an = a+(n-1)d

15 = -1+(n-1)4

15+1 = 4n-4

16+4 = 4n

20 = 4n

20/4 = n

5 = n

OR

n = 5

Step-by-step explanation:

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