Question 354034
Let x be the number of liters of 2% saline solution. Since the desired product is 1 liter solution, then the number of liters of 4% saline solution will be 1-x.
{{{ 2x+4(1-x)=3.6*1 }}} simplify
{{{ 2x+4-4x=3.6 }}} combine like terms
{{{ -2x+4=3.6 }}} subtract 4 from each side
{{{ -2x=3.6-4 }}}
{{{ -2x=-0.4 }}} divide both sides by -2
{{{ x=0.2 }}} so we will need 0.2 liters of the 2% solution, and 1-0.2=0.8 liters of the 4% solution.