Question

math worksheet answer with explanation ​

Answer 1

Answer:

I know that answer

step by step answer:

Sn=78

--n/2 (2a+(n-1)d)=78

--n/2 (2×24+(n-1)(-3))=78

--n(48-3n+3)=78×2

-- ౼3nsquare+51n౼156=0

-- 3nsquare ౼51n+156=0

hah I think this will help you

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