Find the missing length of the triangle

What can you determine about the solutions of this system

Bag a contains 3 white marveled and 2 marbles bag b contains 6 white marbles and 3 red marbles a person draws one marbles from each bag find the probability that both marbles are white

Which pair of expressions is equivalent? a 7(1–k)and7–k b 7(1–k)and1–7k c 7(1–k)and7–k d 7(1–k)and7–7k