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How do I do 1(a)? Please help, urgent!

How do I do 1(a)? Please help, urgent!-example-1
User Fusyion
by
5.7k points

1 Answer

2 votes

Answer:

3n² + 8n

Explanation:

∑ (5 + 6r )

= ∑ 5 + 6 ∑ r

= 5n + 6 ×
(1)/(2) n(n + 1)

= 5n + 3n(n + 1)

= 5n + 3n² + 3n

= 3n² + 8n


User Tiomno
by
5.1k points
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