When simplified, the sum1 + 1+1 + 1+1 +......+ 1 is equal

When simplified, the sum 1 + 1 + 1 + 1 + 1 +......+ 1 is equal to
2 6 12 20 30 n(n+1)

Expression =	1	+	1	+	1	+	1	+ .......... +	1
	2		6		12		20		n(n + 1)

=	1	+	1	+	1	+	1	+ .......... +	1
	1 × 2		2 × 3		3 × 4		4 × 5		n(n + 1)

= 1 -	1	+	1	-	1	+	1	-	1	+	1	-	1	......... +	1	-	1
	2		2		3		3		4		4		5		n		n + 1

Expression = 1 -	1	=	n + 1 - 1	=	n
	n + 1		n + 1		n + 1

When simplified, the sum	1	+	1	+	1	+	1	+	1	+......+	1	is equal to
	2		6		12		20		30		n(n+1)

	2(n + 1)
	n