Question

prove that the sum of first n even number= n(n+1)
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Answer 1

Answer:

2n+n

Step-by-step explanation:

n(n+1)

n×n+n×1

2n+n

Answer 2

Step-by-step explanation:

even numbers are 2 ,4 ,6 ,..........

here , first term,a = 2

common difference,d = 2

Sn = n/2 [ 2a + (n-1)d ]

= n/2 [ 4 + (n-1) 2 ]

= n [ 2 + n- 1]

= n( n+1)

I HOPE THIS MAY HELP YOU