[tex]x-y=350 \\ \frac{2}{5} \ din \ x=56+\frac{3}{4} \ din \ y \\ \frac{2x}{5}=\frac{3y}{4}+56 \\ \frac{8x}{20}=\frac{15y}{20}+\frac{1 \ 120}{20} \\ \Rightarrow 1 \ 120=8x-15 y \\ x=350+y \\ \Rightarrow 8(350+y)-15y=1 \ 120 \\ 2 \ 800+8y-15 y=1 \ 120 \\ 2 \ 800 -7y=1 \ 120 \\ 7y=2 \ 800-1 \ 120=1 \ 680 \\ \Rightarrow \boxed{y=\frac{1 \ 680}{7}=\boxed{240}} \\ x=350+240 \\ \Rightarrow \boxed{x=590}[/tex]
