Ответ:

(4; -5)

Объяснение:

5х+2у=10 помножимо на -2

7х+4у=8

-10х-4у=-20

 7х+4у=8

-3х   =   -12;     х=4

7*4+4у=8;   4у=8-28;   4у=-20;  у=-5

Verified answer

[tex]\displaystyle\bf\\\left \{ {{5x+2y=10} \ |\cdot(-2)\atop {7x+4y=8}} \right. \\\\\\+\left \{ {{-10x-4y=-20} \atop {7x+4y=8}} \right. \\-----------\\-3x=-12\\\\x=-12:(-3)=4\\\\2y=10-5x=10-5\cdot4=10-20=-10\\\\y=-10:2=-5\\\\Otvet \ : \ (4 \ ; \ -5)[/tex]