Question 904669
The general solution for this kind of problem is thoroughly discussed here:


<s><a href="http://www.algebra.com/my/Two-Part-Mixture-with-one-material-quantity-unknown.lesson?content_action=show_dev">http://www.algebra.com/my/Two-Part-Mixture-with-one-material-quantity-unknown.lesson?content_action=show_dev</a></s>


THAT was not the lesson needed;
but THIS was what I meant:
<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>