Find the sum. 0+3+6 + ... + (3n-3)

Step-by-step explanation:

a1 = 0

an = a1 + (n - 1) * d = 3n - 3

a1 = 0

(n - 1) * d = 3 (n-1)

From which d = 3

Now for the sum

Sum = (a1 + an) * n/2

Sum = (an * n) / 2

Sum = 3 (n - 1) * n / 2

Sum = (3n - 3) * n/2

Sum = (3n^2 - 3n) / 2