Question 837122
u = ounces of 15% acid
v = ounces of 25% acid


{{{(15u+25v)/20=21}}} and {{{u+v=20}}}
Solve these two simultaneous equations for u and v.


More guidance how this works, http://www.algebra.com/my/Mixtures%3A-All-in-Symbols.lesson?content_action=show_dev