Question 66904
Graph the following inequalities: 3x - 4y < 12.
:
3x - 4y < 12
:
Put it in the general"y=" form:
-4y < 12 - 3x
We need y to be positive, multiply equation by -1, when you do this, you have to
reverse the inequality sign:
+4y > +3x - 12
y > (3/4x) - 12/4
y > .75x - 3, use decimals for convenience here.
:
Substitute these values for x and find y:
I chose a range of -4 to +8
:
x = -4, substitute -4 for x in the equation:
y = .75(-4) - 3
y = -3 - 3
y = -6
:
x = 0, do the same here
y = .75(0)- 3
y = 3
:
x = +8, and here
y = .75(8) - 3
y = 6 - 3
y = + 3
:
A table would look like:
x | y
-----
-4|-6
 0|-3
+8| 3
:
Choose a convenient scale that will contained these coordinates, plot them.
Your graph should look like this:
{{{ graph( 300, 200, -10, 10, -10, 6, .75x-3) }}}
:
Remember our equation: y > .75x - 3, the "greater than" means the area is above
but not at the line.