Math Is Fun Forum

grr82bntx

Member

Registered: 2007-09-14

Posts: 2

Linear Inequalities

Hello All!!

I need help...lots of help...I need it broken down Barney-Style!! I am just not understanding how to do linear inequalities.

How do you know which side to start, which side to bring the number, which side to bring the letters...and when to reverse the greater/less/equal to signs. I need to understand why and how things are done....and it really is not making sense to me.

I am using ALEKS but there are portions of the explanation that are not mentioned as I guess it is implied. I even have Algebra for Dummies and again, it is not broken down step-by-step so that I can understand wby and how I am doing each step.

Here is an example of a problem:

3z-3<-2/3z-7

(2/3z is a fraction, not sure how to do that otherwise)

Another example is:

-4/3y-7>5y-8
           - (that is supposed to be directly under the greater than - I am assuming it is greater than only because the 7 is greater than the 5, not that I know the if it really is given the other numbers in the equation).

Okay, if someone has some time, can explain this I would REALLY appreciate it. I Do not think that you can dummy it too far...in fact, I would really appreciate it if you would...the easier to understand the better...

Thanks in advance!!

teo

Member

Registered: 2007-08-04

Posts: 7

Re: Linear Inequalities

well, for a start, just try the method of moving all the numbers and letters to the left side and giving it a common denominator. then multiply both sides by the square of the demoninator so as to get rid of the denominator. then plot the graph so that you can find the regions where it will be above or below zero.

switching the signs of an inequality is only needed when you are dividing or multiplying both sides by a negative number.

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to take the first step is easy, to climb up the mountain is another matter.

grr82bntx

Member

Registered: 2007-09-14

Posts: 2

Re: Linear Inequalities

As of yet, I do not have to graph and trying to move both the numbers and the letter to the left side is not working....I have to have something that looks like w< -2/3

teo

Member

Registered: 2007-08-04

Posts: 7

Re: Linear Inequalities

are you refering to the first or the second example?

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to take the first step is easy, to climb up the mountain is another matter.