second term of an ap is 7 more than 6th term of ap and 8th term of ap is 70 find ap and 100th of the ap
Answers
Answer:
given second term of the AP is 7 more than 6th term of ap and 8th term of ap is 70.
we can write second term of the AP = = a +(2-1)d
= a + d
similarly 6th term of the AP = a + 5d
according to the question
second term of the AP - 6th term of the AP = 7
(a+d) - (a+5d) = 7
a +d-a-5d = 7
-4d = 7
d = -4/6 = -2/3
given 8th term of the AP = 70
a + (n-1)d =a(n)
a + (8-1)(-2/3) = 70
a+( 7 ) (-2) = 70× 3
a + 7= 210/-2
= -105
a = -105 -7
a = -112
a(100) = -112+(100-1)(-2/3)
= -112 + 99 (-2/3)
= -178
Answer:
given second term of the AP is 7 more than 6th term of ap and 8th term of ap is 70.
we can write second term of the AP = = a +(2-1)d
= a + d
similarly 6th term of the AP = a + 5d
according to the question
second term of the AP - 6th term of the AP = 7
(a+d) - (a+5d) = 7
a +d-a-5d = 7
-4d = 7
d = -4/6 = -2/3
given 8th term of the AP = 70
a + (n-1)d =a(n)
a + (8-1)(-2/3) = 70
a+( 7 ) (-2) = 70× 3
a + 7= 210/-2
= -105
a = -105 -7
a = -112
a(100) = -112+(100-1)(-2/3)
= -112 + 99 (-2/3)
= -178