Calcule o valor de x nos casos abaixo, sabendo que y = 3. a) 7x + 2y + x + 2y = 0 b) 2x + 3y - x + 3x = 5 c) 1/3x + 1/5y = 0 d) 1/2x + 1/3x + 1/4y = 2 e) 0,25x - 0,30x - 0,35x + 1,2y = 2 f) 0,25x - 0,3y - 0,35y + 1,20y = 0 alguém consegue me ajudar com esses exercícios por favor?

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.