<span>The limitation of
algebra that leads development of calculus is that it can make a complex number
of variables present it as a single variable and then apply the necessary
formula needed to find the answer. After manipulation, the presented single
variable can be changed back to a complex variable by substitution</span>
an = 2 an-1 means that each term in the sequence( except the first) is obtained by multiplying the last term by 2, so the first 4 terms are m, 2m, 4m, 8m.