Question

can you solve this
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Answer 1

✧ The given sequence are in AP .

Because the common difference is same .

✧Sn =n/2 [2a+(n-1)d]

✧14 terms of the sequence is taken , so that their sum is 70

hope this helps you☺️☺️

Answer 2

Answer:

sequence contain 14 terma to get sum 70

Step-by-step explanation:

GIVEN:-

Sn=70

a=-8

d=-6-(-8)=-6+8=2

n=??

solution:-

Sn=n/2 {2a+(n-1)d}

70=n/2 {2×-8+(n-1)×2)

140=n{-16+2n-2}

140=n{-18+2n}

140=-18n+2n²

2n²-18n-140=0

by dividing eq∧n by 2

we get,,

n²-9n-70=0

by solving this quadratic equation

n= -5 or 14

∵n can never be negative

∴n=14

∴the sequence contain 14 terma to get sum 70