Question 1062641
<pre>
{{{matrix(1,3,

expr(matrix(1,3,liters,of,alcohol)/matrix(1,3,liters,of,liquid))*"100%",

""="",

percentage)}}}<pre>After we add x liters of alcohol, 

1.  we will then have 2+x liters of alcohol.

And since alcohol is liquid, we begin with 28+2 liters
of liquid, and when we add x more liters of liquid alcohol,

2.  we will then have 28+2+x liters of liquid.

{{{expr((2+x)/(28+2+x))*"100%"}}}{{{""=""}}}{{{12.5}}}

{{{expr((2+x)/(30+x))*"100%"}}}{{{""=""}}}{{{12.5}}}

Multiply both sides by 30+x:

{{{(2+x)*"100%"}}}{{{""=""}}}{{{12.5(30+x)}}}

{{{200+100x}}}{{{""=""}}}{{{375+12.5x}}}

{{{100x-12.5x}}}{{{""=""}}}{{{375-200}}}

{{{87.5x}}}{{{""=""}}}{{{175}}}

{{{x}}}{{{""=""}}}{{{175/87.5}}}

{{{x}}}{{{""=""}}}{{{1750/875}}}

{{{x}}}{{{""=""}}}{{{2}}} liters of alcohol.

Edwin</pre>