The eleventh term of an A.P is 25 and its 1st term is -3. Find its common difference
a1 = 1 , a11 = 25
The n-th term of A.P.
an = a1 + ( n - 1 ) d
In this case:
a11 = a1 + ( 11 - 1 ) d
a11 = a1 + 10 d
25 = - 3 + 10 d
Add 3 to both sides
28 = 10 d
Divide both sides by 10
2.8 = d
d = 2.8
Your A.P:
- 3 , - 0.2 , 2.6 , 5.4 , 8.2 , 11 , 13.8 , 16.6 , 19.4 , 22.2 , 25
a1 = 1 , a11 = 25
The n-th term of A.P.
an = a1 + ( n - 1 ) d
In this case:
a11 = a1 + ( 11 - 1 ) d
a11 = a1 + 10 d
25 = - 3 + 10 d
Add 3 to both sides
28 = 10 d
Divide both sides by 10
2.8 = d
d = 2.8
Your A.P:
- 3 , - 0.2 , 2.6 , 5.4 , 8.2 , 11 , 13.8 , 16.6 , 19.4 , 22.2 , 25
Correct
pls can help with this mathematics for me
if the First terms of an a.p is 25 and fifth terms is 17 . calculate the following.
1 15 terms
2 9 terms + 6 terms
3 10 terms _ 3 terms
4 6 terms ÷2 terms
First =25, fifth =17 d=17-25 =8 .
l = a+(n-1)d
17 = a+(7-1) -8
17 =a+(2×-8)
17=a+(-16)
17 =a-16
a=17+16
17=a-16
a = 17+25
a=42, d=-8