Homework Help: Algebra

Posted by Casey on Tuesday, February 12, 2013 at 2:58pm.

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?

Algebra - Steve, Tuesday, February 12, 2013 at 4:16pm
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.

Answer this Question

Related Questions

Algebra - Solve the following system of linear inequalities by graphing. x-3y&...
algebra - for the system of inequalities y >= 2x - 1 and y <= 3x...
algebra - for the system of inequalities y >= 2x - 1 and y <= 3x...
pre-calculus - Solve eacy system of inequalities. If the system has no solution...
Algebra - To solve the system of equations, which expression could be ...
advance algebra - 1. 2(6x+13)-7 >= 21 ">=" is greater ...
math/algebra - how do I solve system of linear inequalities by graphing x-y&...
algebra - Solving inequalities and graphing: y<2x+4 -3x-2y greater than ...
advance algebra - 1. 2(6x+13)-7 >= 21 ">=" is greater ...
Pre Cal.--Check my work? - Solve the system of equations: x - y - z = 2; x + 2y...

For Further Reading

First Name:
School Subject:
Answer: