Question 986227
Check these two lessons:


<a href="http://www.algebra.com/my/Mixtures%3A-All-in-Symbols.lesson?content_action=show_dev">http://www.algebra.com/my/Mixtures%3A-All-in-Symbols.lesson?content_action=show_dev</a>


This example maybe easier but the same idea,
<a href="https://www.youtube.com/watch?v=-REjxT9KCzQ">video example, two-part mixture, using just ONE variable</a>