2/3 written as a fraction with a denominator of 9

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

When only separate discreet points are graphed it is called?

Find dy/dx using implicit differentiation ln(20+e^xy)=y