In AP:
an = a + ( n - 1 ) d
where
an = n-th term
a = first term
d = common difference
In this case:
n = 10
a10 = 68
d = 7
a10 = a + 9 d
a + 9 d = 68
a + 9 • 7 = 68
a + 63 = 68
a = 68 - 63
a = 5
The 10terms of an arithmetic progression is 68 and the common difference is 7 find the first terms of sequence
3 answers
term(n) = a + (n-1)d
term(10) = a + 9(7) = 68
a + 63 = 68
a = 5
term(10) = a + 9(7) = 68
a + 63 = 68
a = 5
Soln
Given the 10th term=68
Common difference=7
Then. From:
An=A1+(n-1)d
A10=A1+(10-1)7
A10=A1+(9)7
68=A1+63
68-63=A1
A1=5
: .The first term is 5
Given the 10th term=68
Common difference=7
Then. From:
An=A1+(n-1)d
A10=A1+(10-1)7
A10=A1+(9)7
68=A1+63
68-63=A1
A1=5
: .The first term is 5