Question

Sum of first 4 term of
arithamatic sequence is 72 sum of
first 9 term is also 72.

•write the sequence​

Answer 1

Step-by-step explanation:

S4 = 4/2(2a+(4-1)d)

S4 = 2(2a+3d) = 72

S4 = 2a+3d = 36. ------>1

S9 = 9/2(2a+(9-1)d) = 72

S9 = 9/2(2a+8d) = 72

S9 = 2a+8d = 16 ---->2

S4 = 2a+3d = 36

S9 = 2a+8d = 16

sub s4-s9

36-16=2a+3d-2a-8d

20 = -5d

d = -4

substituting d in 1

2a+3d = 36

2a+3(-4) = 36

2a-12 = 36

2a = 36+12

2a = 48

a = 48/2

a = 24

Series

24,20,16,12,8,..