Consider this sequence. 2, -4, 8, -16 Find the 10th term. Then, what is the sum of the first 10 terms?
Answers
Answered by
7
2 -4 8 -16 32 -64 128 -256 512 -1024
now add
2−4+8−16+32−64+128−256
+512−1,024
=-682
now add
2−4+8−16+32−64+128−256
+512−1,024
=-682
Answered by
2
given.a=2 , d=-4-2=-6
a10=a+(10-1)×d=2+9×-6=2-54=-52
now S10=n/2{2a+(n-1)d}=10/2{2×2+(10-1)×-6=5(4-54)=5×-50=-250
thank u hope it helps!^_^
a10=a+(10-1)×d=2+9×-6=2-54=-52
now S10=n/2{2a+(n-1)d}=10/2{2×2+(10-1)×-6=5(4-54)=5×-50=-250
thank u hope it helps!^_^
shuklashit:
I think this terms are in GP not in AP and the common ratio is -2
if these are in AP then -4-2=-6 but 8-(-4) = 12
yeah u are correct
I didn't see that
btw can u tell what is GP, I don't know it I have not studied it yet
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