Friday

August 22, 2014

August 22, 2014

Posted by **Katie A** on Friday, September 30, 2011 at 11:56pm.

-2x>1/9

- math -
**Steve**, Saturday, October 1, 2011 at 6:08amI guess that means that you multiply both sides by the reciprocal of the coefficient thusly:

-2x * 1/-2 < 1/9 * 1/-2

x < -1/18

Have you wondered why multiplying by a negative flips the direction of the inequality? It's just a shorthand way of moving items to the other side.

-2x < 4

Now suppose you want +2x: Just add 2x to each side

-2x + 2x < 4 + 2x

0 < 4 + 2x

Now subtract 4 from both sides:

-4 < 2x

But that's the same as

2x > -4

which is what you get by multiplying by -1 and swapping direction.

**Related Questions**

Math 116a Fraction - Solve using the multiplacation method -2x>1/9 {x x } I ...

Math 116a - solve using the addition and multiplacation principles 1+6x<49 ...

math - Can someone please check my work? Solve using substitution method 1. 3x+...

Calculus - Volume By Integration - Find the volume of the solid generated by ...

Substitution Method-Plz help - Use the Substitution method to solve the system ...

math - 1. solve by using the quadratic formula. 5x^2+x=3 2. solve by completing ...

Math - Solve by eliminnation methods 2x-4y=5 2x-4y=6 solve the system by ...

algebra2 - Using complete sentences, explain which method you would use to solve...

5s method - how do you solve this problem... solve 6x3 using the 5s method

5s method - how do you solve this problem... solve 6x3 using the 5s method