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Help I don't know how to do this

Help I don't know how to do this-example-1

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1 vote

Answer:

Explanation:

a(n) = a(1) + (n-1)d

a(n) = -9 + (n-1) x (-6-(-9)

a(n) = -9 + (n-1) x (-6 +9)

a(n)= -9 + (n-1) x 3

a(n) = -9 + 3n - 3

a(n) = 3n - 12

a(30) = 3 x 30 - 12

a(30) = 90 - 12

a(30) = 78

User Yannick MG
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