5 coins are put in a bag. 3 of the coins are weighted with the probability of flipping heads being three times as great than the
probability of flipping tails; the remaining coins are fair. One of these coins is selected at random and then flipped once. What is the probability that a weighted coin was selected given that heads was flipped?
You first subtract the 4x to the right side, then you have your answer. This equational term is called Point-Slope Form. The answer is "y=-4x+5" or "Y=5-4x"