37 номер Система уравнений

$\left \{ {{5x+3y=2} \atop {4x+4y=1}} \right.$
$\left \{ {{5x+3y=2} \atop {4y=1-4x}} \right.$
$\left \{ {{5x+3y=2} \atop {y= \frac{1-4x}{4}= \frac{1}{4}-x }} \right.$
$5x+3( \frac{1}{4} -x)=2$
$5x+ \frac{3}{4} -3x=2$
$2x=1 \frac{1}{4}$
$x= \frac{5}{8}$
$y= \frac{1-4* \frac{5}{8} }{4} = \frac{1- \frac{5}{2} }{4} = \frac{1}{4} - \frac{5}{8} = \frac{2}{8} - \frac{5}{8} =- \frac{3}{8}$

$x-y= \frac{5}{8} -(- \frac{3}{8} )= \frac{5}{8} + \frac{3}{8} = \frac{8}{8} =1$

Ответ: А