Answer:
The numbers are 4 and 8.
Step-by-step explanation:
First, you have to form equations for the given informations :
[tex]x + y = 12 - - - (1)[/tex]
[tex]x - y = - 4 - - - (2)[/tex]
Next, you have to solve the simultaneous equations :
[tex](1) - (2)[/tex]
[tex]2y = 16[/tex]
[tex]y = 16 \div 2[/tex]
[tex]y = 8[/tex]
[tex]substitute \: y = 8 \: into \: (1)[/tex]
[tex]x + 8 = 12[/tex]
[tex]x = 12 - 8[/tex]
[tex]x = 4[/tex]