SOLUTION: Graph the inequality on a plane. 3x + 4y < 12.

Algebra ->  Distributive-associative-commutative-properties -> SOLUTION: Graph the inequality on a plane. 3x + 4y < 12.      Log On


   



Question 249969: Graph the inequality on a plane.
3x + 4y < 12.

Answer by College Student(505) About Me  (Show Source):
You can put this solution on YOUR website!
Graphing the inequality: 3x%2B4y%3C12

Steps:
1. In order to graph a line, we need at least two points in the cartesian plane.
2. Set the inequality in y term.
3. To find a point, replace x with a numeric value and solve for y.
4. The x value and the y value will constitute your first point.
5. Do the same thing with a different x value... you will get another y value.
6. Plot both points in the cartesian plane.
7. Trace a solid line if we are working with an equation.
8. Trace a solid line if we are working with either >= or <=
9. Trace a dashed line if we are working with an inequality > or <

Let's get to work:
3x%2B4y%3C12
4y%3C-3x%2B12
y%3C%28-3%2F4%29x%2B%2812%2F4%29
y%3C%28-3%2F4%29x%2B3

Since we are working with a "less than" inequality, we need to draw a dashed line. However, I don't know how to make it look line a dash line using this tool, so instead I'll show the graph with a solid line. Please bear in mind it should be a dashed line.

Also, when graphing inequalities, we need to shade the part of the graph that contains valid values of y. For instance, in this problem, since we are working with "y is less than...", we will need to draw a dashed line AND shade the area below the line.

Below is the graph coresponding to equation y=(-3/4)x+3
REMEMBER: you're going to draw a dashed line and shade below the line.
graph+%28400%2C+400%2C+-10%2C+10%2C+-10%2C+10%2C+%28-3%2F4%29x%2B3%29