Question

The formula for the nth term, an, of an arirhmetic progression is given by an = a1 + (n - 1)d, where a1 represents the first term of the progession and d represents its common difference. What is the value of the 20th term of the arithmetic progression 4, 7, 10,...?

Answer 1

need help

Answer 2

a1 in this case is 4
d in this case is 3(since 3 is added to get to next sequence)
We want n=20th term
4+(20-1)3
4+19*3

Answer 3

its result is 48

Answer 4

i don't know why?

Answer 5

sorry its result is 56

Answer 6

i don't know why?

Answer 7

ok you right it is 61

Answer 8

am so sorry

Answer 9

4+19*3=61
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61

Answer 10

but how you know d =3?

Answer 11

sequence goes up by 3

Answer 12

You add 3 to get to next sequence

Answer 13

oh I see it

Answer 14

thank you very much

Answer 15

no problem