Answer:
[tex]the \: two\: numbes \: are : \\ 7.777 \: and \: - 2.099[/tex]
Step-by-step explanation:
[tex]let \: the \: two \: numbers \: be : x \: and \: y \\ x + y = 5.678.....eq(1) \\ x - y = 9.876 .....eq(2)\\ x = 9.876 + y....from \: eq(2) \\ y = 5.678 - x....frm \: eq(1) \\ eq \:...y \: in \: terms \: o f\: x : \\ x = 9.876 + 5.678 - x \\ 2x = 15.554 \\ x = 7.777 \\ y = 5.678 - x = y = 5.678 - 7.777 \\ y= - 2.099.[/tex]