Posted by **m** on Thursday, September 8, 2011 at 4:58pm.

i need help solving these inequalities i'm not sure if i should factor things out or not

4x^3 is greater than or equal to 16x

and

4 is greater than or equal to 2x^3 + 8x

- algebra 2 -
**MathMate**, Sunday, September 11, 2011 at 9:41am
Yes, you can factor out *numbers* which are positive as in equations.

4x>16 can be written as

x>4

(common factor 4 is positive.)

If the factor is negative, you can still factor it out, *but* you will need to reverse the sign of inequality.

-5x ≥ 40

x ≤ 40/(-5)

x ≤ -8

(common factor -5 is negative)

If the sign of the factor is unknown, then you'll have to make different cases:

ax > ab

x > b (if a>0)

x < b (if a<0)

x is undefined if a=0

## Answer this Question

## Related Questions

- Algebra - Use a graphing calculator or a computer to graph the system of ...
- Algebra--Correction? - Solve x^2 -3x is greater than or equal to 10 Would the ...
- College Algebra - How do you solve this to graph the system of inequalities? x+...
- Algebra - Did I do this correctly? 13 - (2c + 2) >(pretend it has the line ...
- algebra/ inequalities - Posted by lauren on Thursday, April 17, 2008 at 8:45pm ...
- algebra - use the inequality -4t-8 is less than or equal to 12 a. t is greater ...
- physics - A beam of electrons with momentum p=10^-23 kg m/s passed through a ...
- algebra - Solving inequalities and graphing: y<2x+4 -3x-2y greater than or ...
- Math - I'm having a hard time with graphing this problem. Could someone please ...
- math - State the null hypothesis, Ho, and the alternative hypothesis, Ha, that ...