Question

The first term of an arithmetic sequence is -5, and the tenth term is 13. Find the common difference.


8/9
1.8
2

Answer 1

do you know the formula for n'th term of arithmetic sequence ?

Answer 2

no wat u see is all i have

Answer 3

its this :
\(\large a_n=a_1+(n-1)d\)
an is the n'th term,
a1 = 1st term, here a1 = -5
d = common difference

Answer 4

if we have 10th term, you just plug in n=10
and a10 is given = 13

Answer 5

so put
n=10
an =13
a1 = -5
in that formula!
only "d" is unknown, can you find it ?

Answer 6

no...

Answer 7

@hartnn

Answer 8

no ? whats the problem you are facing ?
you have the formula, and the values, did you try plugging in ?

Answer 9

i hav tried but i just dont get it. math is my worst subject so yea

Answer 10

we have
13 = -5 + (10-1)d
yeah ?
start by adding 5 on both sides, what do u get ?

Answer 11

ummmm 17 and 0?

Answer 12

13+5 =18

Answer 13

oh whoops

Answer 14

so, 18 = 9d
just divide 9 on both sides,
d= .. ?

Answer 15

1?

Answer 16

how?

Answer 17

2?

Answer 18

yes!

Answer 19

thanx

Answer 20

welcome ^_^