Respuesta :

Answer:

a = -2

Step-by-step explanation:

The graphs of the lines would have to be parallel.  So they must have the same slope.   2x + y = -1 changed to slope-intercept form is y = -2x - 1.  Therefore, the slope of that line is -2.   y = ax is in slope-intercept form where the slope is a.  So, a must equal -2.