Question 1156695
e, Empire at $1.40
r, Red delicious at $1.10
g, Golden delicious, at $1.30
{{{r=2e+2g}}}----------directly from description


{{{system(e+r+g=21,1.4e+1.1r+1.3g=25,r=2(e+g))}}}


or  by substitution
{{{system(e+2e+2g+g=21,1.4e+1.1*2*(e+g)+1.3g=25)}}}

{{{system(3e+3g=21,1.4e+2.2e+2.2g+1.3g=25)}}}

{{{system(3e+3g=21,3.6e+3.5g=25)}}}


{{{system(e+g=7,3.6e+3.5g=25)}}}