You toss n balls into n bins. for each toss there is a 1/n probability that the ball you toss lands in any one of the bins. after n tosses, what is the expected number of empty bins?

One unique triangle, because those angles add up to 180, and that's how many degrees there are in one triangle.

1. use commutative property to reorder the terms.2x+81=0.2. move the constant to right side by adding its opposite on both sides. 2x+81-81=0-81.2x=(-81).3. divide the equation on both sides.2x ÷ 2 = 81 ÷ 2.x = -81/2. your answer is -81/2. if you need to simplify it into a decimal, it’s -40.5.