- Joined
- Apr 12, 2005
- Messages
- 11,339
Did you strugle with Equalities? These are only barely different. There is only one extra rule - swicth the inequality when multiplying or dividing by a negative value.
Y>2/3x - 3
Add 3
Y + 3 > (2/3)*x
Multiply by 3/2 (a positive number)
(3/2)*(Y + 3) > x
Are we graphing? Just graph the equality and think about it.
Y = (2/3)*x - 3
Start at (0,-3), the Y-intercept.
Move to (3,-1), just using the slope to find another point.
This gives you a line.
There are now two things to consider.
1) Is it '<' or '<='? Is it '>' or >="? If the '=' is in there, make a solid line. If there is no '=', make it a dotted line.
2) Pick a point and try it out. I like to use (0,0), if possible, since it tends to be simpler to evaluate. 0 > (2/3)*0 - 3?? 0 > -3?? Yes! If it works, shade the side containing the point you tested. If it doesn't work, shade the other side.
OK, you do one. Of course, it would help if we know what we were supposed to be doing. "solving the following problems" is an inadequate description.
Y>2/3x - 3
Add 3
Y + 3 > (2/3)*x
Multiply by 3/2 (a positive number)
(3/2)*(Y + 3) > x
Are we graphing? Just graph the equality and think about it.
Y = (2/3)*x - 3
Start at (0,-3), the Y-intercept.
Move to (3,-1), just using the slope to find another point.
This gives you a line.
There are now two things to consider.
1) Is it '<' or '<='? Is it '>' or >="? If the '=' is in there, make a solid line. If there is no '=', make it a dotted line.
2) Pick a point and try it out. I like to use (0,0), if possible, since it tends to be simpler to evaluate. 0 > (2/3)*0 - 3?? 0 > -3?? Yes! If it works, shade the side containing the point you tested. If it doesn't work, shade the other side.
OK, you do one. Of course, it would help if we know what we were supposed to be doing. "solving the following problems" is an inadequate description.
