Let's call the first number x, and the second number y. Putting what you have said into equation form:
[tex]x+2y=13
\\\\4x+2y=-2
[/tex]
Subtracting one equation from another gives:
[tex]x+2y=13 \\-(4x+2y=-2)
\\\\-3x=15
\\x=-5[/tex]
If x = -5,
[tex]x+2y=13
\\(-5)+2y=13
\\2y=18
\\y=9[/tex]
So the first number is -2, the second number is 9