[tex]4x +3y = 15 \\ 4x + y = 13[/tex]
[tex]4x + y = 13 \\ y = -4x + 13[/tex]
[tex]4x + 3(-4x+13) = 15 \\ 4x -12x +39 = 15 \\ -8x = -24 \\ x = 3[/tex]
[tex]4x + 3y = 15 \\ 4(3) + 3y = 15 \\ 12 + 3y = 15 \\ 3y = 3 \\ y=1[/tex]
[tex]4x + 5y \\ 4(3) + 5(1) \\ 17[/tex]
$17