Question 759123
How many milliliters, v,  of H% acid are mixed with U milliliters of L% acid to produce a mixture that is T% acid? Round to the nearest whole number.


Some requirement of order in those variables is {{{0<L<T<H<100}}}.


{{{(LU+Hv)/M=T}}} and {{{U+v=M}}}.
The only unknown variable is v.  Solve the system for v.  Actually, only one equation is needed.  The material sum equation for M can be used directly giving:


{{{highlight((LU+Hv)/(U+v)=T)}}}
As directed, solve for v.