Warm Up Solutions

$\begin{array}{rcl} 2 P E & = & k x^{2} \\ k & = & \frac{2 P E}{x^{2}} \end{array}$

Note

You should know how to isolate variables in formulas. In Algebra 1, you learned to work backward to undo the operations being performed in a problem.

The ratio of string players to percussionists in the orchestra is 7 to 2. If there are 42 string players, how many percussionists are in the orchestra? Write and solve a proportion.

$\begin{array}{rcl} \frac{7}{2} & = & \frac{42}{p} \\ 7 p & = & 84 \\ p & = & 12 \end{array}$

Note

It is recommended that you set the problem up as a proportion and find the cross-product.

Q: What is the total number of orchestra members for this problem?

A: 42 + 12 = 54 players.