Respuesta :
Hello back,
18=(x+y)/3
18=(x-y)*3/5
==>(x+y)/3=(x-y)*3/5
==> 5(x+y)=9(x-y)
==>5x+5y=9x-9y
==>4x=14y
==>x=7/2y
18=(7/2y+y)/3
==>9/2*y=18*3
==>y=12
==> x=7/2*12=42
Sorry for the error.
18=(x+y)/3
18=(x-y)*3/5
==>(x+y)/3=(x-y)*3/5
==> 5(x+y)=9(x-y)
==>5x+5y=9x-9y
==>4x=14y
==>x=7/2y
18=(7/2y+y)/3
==>9/2*y=18*3
==>y=12
==> x=7/2*12=42
Sorry for the error.