Question 1013151
x, how many of apple juice
y, how many of orange juice


Account for number of gallon bottles:  x+y=15


Account for the cost of the juices:  1.5x+2y=26


System of equations is  {{{system(x+y=15,1.5x+2y=26)}}}.


A simple modification is multiply the money equation by 2 to get all whole number coefficients:
{{{system(x+y=15,3x+4y=52)}}}



Choosing Elimination Method would be best.
{{{system(3x+3y=45,3x+4y=52)}}}
Subtract first of these from the second of these equations to first get y.