The 7thand 21stterms of an AP are 6 and -22 respectively. Find the 26t...
To find the 26th term of an arithmetic progression (AP), we need to use the formula for the nth term of an AP.
The formula for the nth term of an AP is given by:
an = a + (n-1)d
Where:
an = nth term
a = first term
n = position of the term
d = common difference
We are given:
a7 = 6
a21 = -22
Step 1: Finding the Common Difference (d)
Using the formula, we can find the common difference (d) by subtracting the 7th term from the 21st term:
d = a21 - a7
d = -22 - 6
d = -28
Step 2: Finding the First Term (a)
Using the formula and substituting the values we have for the 7th term and the common difference, we can solve for the first term (a):
a7 = a + (7-1)d
6 = a + 6d
Substituting the value of d:
6 = a + 6(-28)
6 = a - 168
a = 6 + 168
a = 174
Step 3: Finding the 26th Term (a26)
Using the formula and substituting the values we have for the first term and the common difference, we can solve for the 26th term (a26):
a26 = a + (26-1)d
a26 = 174 + 25(-28)
a26 = 174 - 700
a26 = -526
Therefore, the 26th term of the arithmetic progression is -526. However, none of the given options match this answer. So, it seems there might be a mistake in the options provided.
The 7thand 21stterms of an AP are 6 and -22 respectively. Find the 26t...
7th term = 6
21st term = -22
That means, 14 times common difference or -28 is added to 6 to get -22
Thus, d = -2
7st term = 6 = a+6d
⇒ a + (6*-2) = 6
⇒ a = 18
26st term = a + 25d
⇒ 18 - 25*2 = -32.