What is the starting point and and slope of this equation?

The sum of two numbers is 86, and their difference is 20. find the two numbers

33% of college students say they use credit cards because of the rewards program. you randomly select 10 college students and ask each to name the reason he or she uses credit cards. find the probability that the number of college students who say they use credit cards because of the rewards program is (a) exactly two, (b) more than two, and (c) between two and five inclusive. if convenient, use technology to find the probabilities.

Is the square root of 4 plus the square root of 16 rational?