Question

2x-6y = -7 п Решите систему уравнений: 2y-x=-1 в ответе запишите значение разности х у.​

Answer 1

$\displaystyle\bf\\\left \{ {{2x-6y=-7} \atop {2y-x=-1}} \right. \\\\\\\left \{ {{2x-6y=-7} \atop {-x+2y=-1} \ |\cdot 2} \right. \\\\\\+\left \{ {{2x-6y=-7} \atop {-2x+4y=-2}} \right.\\ ----------\\2x-6y-2x+4y=-7-2\\\\-6y+4y=-9\\\\-2y=-9\\\\y=-9:(-2)=4,5\\\\x=2y+1=2\cdot4,5+1=9+1=10\\\\x=10 \ \ \ , \ \ \ y=4,5\\\\\boxed{x-y=10-4,5=5,5}\\\\Otvet \ : \ 5,5$