Answer:
12
Explanation:
The number can be represented as x, so we can write an equation for this
Half the number can be said as 1/2x
19 less can be said with the other equation as 1/2x - 19
So it ends up being
1/2x - 19 = -13
To isolate the x, we add 19 to both sides, which makes it:
1/2x = 6
Multiplying both sides by the denominator makes the equation
x = 12
So the mystery number is 12