Ali writes the expression "half of the sum of $9$ and a number." Write an algebraic expression that is equivalent to Ali's expression. Write a second algebraic expression that is different from, but equivalent to, your first expression.

Fiona and her friends are playing a game by guessing where a coin will land when it is randomly dropped inside the square shown below. fiona guesses that the coin is likely to land in the blue area. which explains whether or not fiona is correct and why?

The circumference of a circle is 5 pi cm. what is the area of the circle?

Neveah and clint are baking muffins for the bake sale. they need to bake 30 muffins for their display case. clint has baked 4 so far, and neveah has baked 7. how many muffins (m) do they have left to bake? show your work!