# Thread: Help with some inequalities

1. ## Help with some inequalities

if theres one thing i really cant do its inequalities. can you guys help me out with some problems which all need to be shown in interval notation,

thanks

1) 2x squared+5x-3<0

2) x squared + 6x +9>0
- (that minus is below the greater than sign)

3) x squared - 49 < 0
-(same with this one to)

2. Originally Posted by Ryan7123
if theres one thing i really cant do its inequalities. can you guys help me out with some problems which all need to be shown in interval notation,
You must post some actual problems to get any help.

3. just did sorry lol i guess i forgot to

4. To learn, in general, how to solve quadratic inequalities, try some online lessons.

Long story short: Find the zeroes (which are where the graph crosses the x-axis). These zeroes will divide the number line into intervals. Once you've found these intervals, consider the graph.

For right-side-up parabolas (that is, for positive quadratics), the graph is below the x-axis (so the quadratic is negative) between the zeroes, and above the x-axis "on the ends" (so the quadratic is positive).

For upside-down parabolas (that is, for negative quadratics), the graph goes the other way 'round.

Using the zeroes and what you know about the graphs, pick the appropriate solution intervals.