단항식의 계산(Calculation of Monomials)

5a times 2b =10 ab : https://goo.gl/SF9bEy YouTube : https://youtu.be/40BZ1-CtoEE

a div b = a times frac{1}{b} ( b>0) : https://goo.gl/Icksiu  YouTube : https://youtu.be/vir_GQJfRwA