Question 295596
v, amount of pure alcohol
{{{100v+70*40=(v+40)*85}}}

{{{100v+70*40=85v+85*40}}}

{{{100v-85v=85*40-70*40}}}

{{{v(100-85)=40(85-70)}}}

{{{v=40((85-70)/(100-85))}}}   Compute this v.