## Precalculus (6th Edition) Blitzer

Step 1. Write an equation using the given statement. Suppose $y=kx$ Step 2. Substitute the given value of $x$ and $y$ in step 1 and find the value of $k$. Suppose $x=2$ and $y=4$ then, \begin{align} & 4=2k \\ & k=2 \\ \end{align} Step 3. Substitute $k=2$ in step 1. $y=2x$ Step 4. Use the equation from step 3 to find the problem question according to given condition.