Migdalia has 6 red marbles, 5 blue marbles, and 1 black marble in a bag. Each marble is the same size and shape. Migdalia pulls out one marble from the bag without looking. What is the probability of Migdalia pulling out a blue marble

x = 10

Step-by-step explanation:

x x 2 + x - 30 = 0          use the commutative property to reorder the terms

2x + x - 30 = 0             collect like terms

3x - 30 = 0                move constant to the right hand side and change its sign

3x = 30                      divide both sides of the equation by 3

x = 10