Step-by-step explanation:
[tex]a_3 [/tex] = - 4
[tex]a_3 [/tex] = a* + (3- 1) d*
- 4 = a + 2d . . . . . . . . .(i)
[tex]a_8 [/tex] = - 29
[tex]a_8 [/tex] = a + ( 8 - 1) d
- 29 = a + 7d . . . . . . . . (ii)
subtracting equations (i) and (ii)
25 = 5d
d = -5
placing d = -5 in equation (i)
a - 10 = -4
a = 6
For an arithmetic Progtession
[tex]a_n [/tex] = a + (n - 1)d
[tex]a_n [/tex] = 6 + (n- 1)-5
[tex]a_n [/tex] = 6 - 5n + 5
[tex] \underline {a_n = 11 - 5n }[/tex]
[tex]\\[/tex]
*[tex] \boxed{ \mathfrak { a \:stands\: for\: first\: term } } [/tex]
*[tex] \boxed{ \mathfrak { d \:stands\: for\: common \: difference } } [/tex]
Answer:
General rule » -5n+11
Step-by-step explanation:
a3 = a+2d = -4 .......(1)
a8=a+7d = -29..........(2)
(2)-(1) » 5d= -25
d = -25/5
. = -5
substitute d = -5 in ( 1)
» a-2×-5= -4
a-10 = -4
a = -4 +10
= 6
General rule » a +(n-1)d
» 6 +(n-1)×-5
» 6-5n+5
» -5n+11
