Question

Find the common difference of the arithemetic a1= -22 and a12 =77

Answer 1

@thomaster

Answer 2

Hi,
do u know the formula to find the nth term of an arithmetic progression ?

Answer 3

\[T _{n} = a + (n-1)d\] ?

Answer 4

TEA THATS IT

Answer 5

no wait no

Answer 6

wt do y mean by that ? Do u know a formula which is different to this one ?

Answer 7

anyway... ya can solve this easily with the one i mention above
u can find the n th term of an arithmetic progression by ...\[T _{n} = a + (n-1)d\]

where
a is the first term...
d is the common difference...
n / Tn is the n th term
now in ur question
a1 is given as -22
so ... we know the first term of this progression.
and the value of 12 th term is also given as 77
now.. if we use that formula to find the 12th term...
\[T _{12} = a + (12 -1)d\]
we know the value of 12 th term and the first term.... so we can rewrite this as...\[77 = -22 + (12 -1)d\]\[99 = 11d\]\[d = 9\]

hope this will help ya out!!!

Answer 8

Thanks so much

Answer 9

u r welcome!!