times to get -12 add to get -5

To find two numbers that add up to -5 when their sum is -12, we can set up the equation:

x + y = -5,
x + y = -12.

Now, we can solve the above system of linear equations. Subtracting the second equation from the first, we get:

(x + y) - (x + y) = -5 - (-12),
0 = -5 + 12,
0 = 7.

Since 0 is not equal to 7, this system of equations has no solution. Therefore, there are no two numbers that add up to -5 when their sum is -12.