The first term of an A.P is 5 and the common difference is -3/2, find the term whose value is -20

6 answers

An = 5 +(n-1) d
-20 = 5 + (n-1)(-1.5)
-25 = -1.5 n + 1.5
-26.5 = -1.5 n
n = 17 2/3
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The first term of an Arithmetic progression is 5 and the common difference is -3/2.find the term whose value is -41/2
Using the formula for the nth term of an arithmetic progression:

an = a1 + (n-1)d

where
an = term whose value is given = -41/2
a1 = first term of the arithmetic progression = 5
d = common difference = -3/2

-41/2 = 5 + (n-1)(-3/2)
-41/2 = 5 - (3/2)n + (3/2)
-46 = (-3/2)n
n = (46/3) + 1

Therefore, the term whose value is -41/2 is the (46/3) + 1th term of the arithmetic progression.