Write an explicit formula for this table hours: 1 2 3 4 5 tweets: 5 15 75 225 675

The explicit formula would be



This is a geometric sequence, since each term is found by multiplying the previous term by a constant.  The explicit form of a geometric sequence is given by



where r is the common ratio, or constant we multiply by, and g₁ is the first term.  For our sequence, g₁ = 5 and r = 3, so our formula is