Find the number of terms in the A.P. : 18,15*1/2,13,....,-47
Answers
Answered by
1
Answer:
Step-by-step explanation:
a= 18
l = -47
d = -21/2
n = ?
l = a + (n-1).d
-47 = 18 - 21n/2 + 21/2. ( -*- = +)
Taking L.C.M.
-47 = ( 36 - 21n +21 )/2
taking 2 on L.H.S.
-94 = 57 - 21n
taking 57 on L.H.S.
-94 -57 = -21n
-151 = -21n
151 = 21n ( - sign will get cancelled on both the sides)
n = 151/21
n = 7.1904
therefore, n = 7. (ignoring decimal numbers)
THEREFORE OUR FINAL ANSWER IS n = 7
Read more on Brainly.in - https://brainly.in/question/6289052#readmore
DIRT:
d=-5/2
Similar questions