Question 727784
VARIABLES
u = how much 10% acid to use, unknown
v = how much 100% acid to use, unknown
M = volume of resulting solution, 90L
L = percent of low concentration acid material to use, 10%
T = intended percent concentration of acid in the resulting solution, 55%


EQUATIONS
{{{highlight((Lu+v)/M=T)}}} AND {{{highlight(u+v=M)}}}


PROCESS
Those are two equations with two unknowns.  Both equations are linear in u and v.  Solve for u and v.  Substitute known and given values to compute u and v.