91Ó°ÊÓ

Show that $C\left(n-1,r\right)+C\left(n-1,r-1\right)=C\left(n,r\right)$.

Evaluate each expression.

${\log }_{2}128$

Evaluate each expression.

${\log }_{3}243$

Evaluate each expression.

${\log }_{9}3$

State whether the events are independent or dependent.

Choosing the color and size of a pair of shoes.

Evaluate each expression

$P\left(5,3\right)$

Simplify each expression.

$-\frac{x^2-y^2}{x+y}·\frac{1}{x-y}$

Simplify each expression.

$\frac{\frac{x^2}{x^2−25y^2}}{\frac{x}{5y−x}}$

Edison is located at $\left(9,3\right)$ in the coordinate system on a road map. Kettering is located at $\left(12,5\right)$ on the same map. Each side of a square on the map represents 10 miles. To the nearest mile, what is the distance between Edison and Kettering?

Solve each equation.

$x^4-5x^2+4=0$