Question

решите способом сложения​

Answer 1

х + у = 5

х - у = 8

х+у-х+у=5-8

2у=-3 ( х сократили)

у = -1,5

Х + (-1,5)=5

Х - 1,5 = 5

Х = 6,5

Answer 2

Объяснение:

$+ \left \{ {{x+y=5} \atop {x-y=8}} \right. \\\left \{ {{x+x+y-y=5+8} \atop {x-y=8}} \right. \\\left \{ {{2x=13} \atop {x-y=8}} \right. \\ \left \{ {{x=6,5} \atop {6,5-y=8}} \right. \\\left \{ {{x=6,5} \atop {y=-1,5}} \right.$