Question 783761
Let p = percent fruit juice in Brand A.


{{{(8p+6*40)/14=20}}}-----Equation representing situation
{{{4p+6*20=14*10}}}
{{{4p+6*4*5=14*10}}}
{{{p+30=7*5}}}
{{{p=35-30=5}}}


Brand A is 5% fruit juice.


Steps can vary, yours do not need to be as unusual as the way I showed.  Generally most important is to first create the equation which characterises the situation and then solve according to some good use of number properties.