whenever you multiply/divide by a negative value, the direction of the inequality changes. It's just a shorthand for moving things to the other side. For example,
-2x < 8
0 < 8+2x
-8 < 2x
-4 < x
or, just dividing by -2 and switching the direction,
x > -4
So, for your problem,
-3x - 2y> 6
-3x-6 > 2y
y < -3/2 x - 3
Also, we have
y < 2x+4
So, to satisfy both equations,
find where the two lines intersect. The solution set is points where y is below both lines.
Solve the system of inequalities.
y<2x+4
-3x - 2y> 6
So I just want y alone. For the second inequality, I added 3x to both sides and got -2y> 3x+6. Then I divided both sides by -2. I got y> -3/2 - 3
Do I have to switch the inequality symbol or something?
1 answer
1 answer