Got a fairly simple looking system of equations, 2k+4y=20, and 3x+6y=30 Don't understand how to prove what values of k provide - 1 solution - no solutions - and many solutions

The table shows a pattern of exponents. what is the pattern as the exponents decrease?

Math each whole number with a rational, exponential expression

Consider a bag that contains 220 coins of which 6 are rare indian pennies. for the given pair of events a and b, complete parts (a) and (b) below. a: when one of the 220 coins is randomly selected, it is one of the 6 indian pennies. b: when another one of the 220 coins is randomly selected (with replacement), it is also one of the 6 indian pennies. a. determine whether events a and b are independent or dependent. b. find p(a and b), the probability that events a and b both occur.