Question

Consider the sequence 4,-12,36,-108... What is the explicit formula that could be used to solve any term in the sequence

Answer 1

Well the difference between each number is multiplied by -3. So you could do y= -3x + 4. X would start at 0 so x= 0 which plugged in would be 4 which is the first answer. For the second number x=1 when plugged in you get y as -12 which is the second number and so on.