The number expressed using exponents

This expression can be written in a shorter way using something called exponents. An expression that represents repeated multiplication of the same factor is called a power.The number 5 is called the base, and the number 2 is called the exponent. For example 

X= 2 he can buy 2 packs of cards for $12 and an action figure for $3 so he would spend $15 in total plus the free poster