Question

what are the first four terms of the sequence represented by the expression n(n-1)-4

Answer 1

come on -- just plug in the values for n. You have the formula
an = n(n-1)-4
so,
a1 = 1(1-1)-4 = -4
a2 = 2(2-1)-4 = -2
...

Answer 2

ok i posted the wrong question so .........