In Oklahoma, there was an earthquake that measured 3.1 on the Richter scale. Six years later, there was an earthquake in the same area that measured 5.8 on the Richter scale. How much more intense was the second earthquake than the first?  Use the formula  to solve. 

Using the formula  , find the intensity of music at 120 decibels.

Solve for x  . Round to the nearest hundredth.  

Check all that apply to the system of equations.

Solve for x:  .

Which polynomial has roots:  ?

Which hyperbola has the asymptotes  and  ?

Which equation is shown in the graph below?  A coordinate plane with labeled x- and y-axes is shown. A red piecewise linear graph forms an inverted V shape with a peak at approximately (1, 2). From the left, the line rises with a positive slope, crossing the y-axis near (0, 1) before reaching the peak. From the peak, the line decreases with a negative slope, crossing the x-axis near (3, 0) and continuing downward to the right. The two line segments meet at the highest point, creating a sharp vertex.

In the graph , the vertex is a _____.

Write the equation  in focus-directrix form.