What are the steps to solve this?

One card is dealt from a 52 card deck. find the probability that the dealt card is a 4 or a black 7

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

Is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis.