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The equivalent expression to ∑n(n+1) is ∑n²+∑n.
Equivalent expressions are defined as algebraic expressions which give the same resulting expression. An algebraic expression (or) a variable expression is defined as a combination of terms by the operations such as addition, subtraction, multiplication, division.
Here, given expression;
∑(n(n+1))
= ∑ (n² + n)
= ∑n²+∑n
Thus, the equivalent expression to ∑n(n+1) is ∑n²+∑n.
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