Twice the difference of a number and 4 equals 20

Asystem of equations has 1 solution.if 4x-y=5 is one of the equations , which could be the other equation ?

What is the value of m in the equation 1/2 m - 3/4n=16 when n=8

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.