Question

For 1 + 2 + 3 + ... + n = n(n + 1)/2, P(k + 1) would be
A. 1 + 2 + 3 + ... + k = k(k + 1)/2
B. 1 + 2 + 3 + ... + (k + 1) = k(k+ 1)/2
C. 1 + 2 + 3 + ... + k = (k + 1)(k + 2)/2
D. 1 + 2 + 3 + ... + (k + 1) = (k + 1)(k + 2)/2

Answer 1

1 + 2 + 3 + ... + n = n(n + 1)/2

simply replace `n` by `k+1`

Answer 2

1 + 2 + 3 + ... + n = n(n + 1)/2

becomes :

1 + 2 + 3 + ... + (k+1) = (k+1)(k+1 + 1)/2

Answer 3

THANK YOU SOOOO MUCH

Answer 4

you're welcome !