Thread: I need to plot these Systems of Inequalities onto a graph. Help!?

How can I find the coordinates to these so I can graph the lines.
y >= 2x-3
y < -4x-5

There should be two lines, right? I need help finding the coordinates for each of the lines and then how I need to shade them. Left side or right side? No idea where to start. I'm a complete idiot when it comes to algebra.
Can someone please help me out here?

Originally Posted by eraser851

How can I find the coordinates to these so I can graph the lines.
y >= 2x-3
y < -4x-5

There should be two lines, right? I need help finding the coordinates for each of the lines and then how I need to shade them. Left side or right side? No idea where to start. I'm a complete idiot when it comes to algebra.
Can someone please help me out here?

When graphing them, treat the inequalities as equalities like so:




Now, graph the lines, and look back at your original inequalities. The first inequality is the entire region above and AT the line . The second region is the entire region below the line . The subspace region where both of these areas intersect is what you should leave as shaded in your graph. That region of x-values satisfies both equations.

Okay, correct me if I'm wrong.

y >= 2x-3 would have coordinates at (-2,-7) and oh lets say (3,3)

y < -4x-5 would have coordinates at (1,-9) and say (-2,3)


Would this be right?

Originally Posted by eraser851

Okay, correct me if I'm wrong.

y >= 2x-3 would have coordinates at (-2,-7) and oh lets say (3,3)

y < -4x-5 would have coordinates at (1,-9) and say (-2,3)


Would this be right?

Close.... would be the region to the left of the line.

Alright, now I'm stuck on a new one.
9x + 7y > -21

Since the 'y' is in the middle, how can I make a 'y=' formula?
And how would I know which side to shade on? Left or right?

Originally Posted by eraser851

Alright, now I'm stuck on a new one.
9x + 7y > -21

Since the 'y' is in the middle, how can I make a 'y=' formula?
And how would I know which side to shade on? Left or right?

Shade to the right of the line