Answer:
a = -4.
Step-by-step explanation:
If the are perpendicular then the slope of one graph will be - 1 / slope of the other.
Convert each equation to slope-intercept form:
x + 2y + 3 = 0
2y = = -x - 3
y = (-1/2)x - 3/2 (Slope/intercept form)
So the slope of the line perpendicular to this will be - 1 / (-1/2) = 2.
Consider the other line:
ax + 2y + 3 = 0
2y = -ax - 3
y = (-a/2) x - 3/2 (Slope/intercept form)
So the slope for this line - a/2 and it equals 2.
-a/2 = 2
-a = 2*2 = 4
a = -4 (answer).
