help me with inequalities

urstruely

New member
Joined
Jan 12, 2006
Messages
2
i dont understand a thing about inequalities when it has more than one number on each side. how do i get one answer. i know that u use the distributive property but i always get the answer wrong. can u give some examples and tell me wat to do step by step. :!:


:cry:
 
an inequality is a number such as 9/3

if you need to convert the number into a real number...say how many times can 3 divide into 9...and your answer will be three
 
urstruely said:
i dont understand a thing about inequalities when it has more than one number on each side. how do i get one answer. i know that u use the distributive property but i always get the answer wrong. can u give some examples and tell me wat to do step by step. :!:


:cry:

The very best way to get a helpful answer here is to
1) Post an example of a problem you are having trouble with
2) Show us, step by step, what you have done to solve the problem

That way, we know exactly what you are asking about, and can see where you have made any mistakes in the solution.

Your question, as posted, requires us to be "mind readers." I, for one, am not very good at reading minds.

All of that said, I will take a guess that you are dealing with problems like this one:
5x - 4 < 2x + 17

Do you realize that solving inequalities is just like solving equations--with one exception. If you multiply or divide both sides of an inequality by a negative number, you need to switch the direction of the inequality symbol. With this in mind, let's solve this inequality.

The first thing we want to do is eliminate the variable term from one side. It is generally a good idea to get rid of the smaller variable term. In this problem, the smaller variable term is 2x; let's add -2x to both sides of the inequality:
5x - 4 + (-2x) < 2x + 17 + (-2x)
Now, combine like terms:
3x - 4 < 17

Next, isolate the variable term (get it by itself). Add 4 to both sides to get rid of the " - 4":
3x - 4 + 4 < 17 + 4
Combine like terms again:
3x < 21

Finally, we want 1x, or just x. To "undo" the multiplication by 3, we need to divide both sides of the inequality by 3. Since we are dividing by a positive number, the direction of the inequality symbol stays the same:
(3x)/3 < 21/3
x < 7

Now we know that the original inequality should be true for any value of x which is less than 7.

If I haven't guessed correctly at the kind of problem you need help with, it is because my crystal ball is dusty and doesn't always give me a clear view of things.
 
not like that kind of inequality

i mean like 5+6m<7. i dont understand how to sole those kind of promblems. :shock:
 
Re: not like that kind of inequality

urstruely said:
i mean like 5+6m<7. i dont understand how to sole those kind of promblems. :shock:

This problem shows that m was multiplied by 6, then 5 was added and the result is less than 7. To solve this type of problem, as shown earlier, you undo what was done by doing the opposite, and you start with the last thing. What we do is done to both sides of the inequality, just as in equations.

5 + 6m < 7 First, take away the 5 that was added:
-5 -5
6m < 2 Now, divide by 6 to undo the multiplication shown:
6m/6 < 2/6
m < 1/3

To check, put 1/3 in for m and see if it works in the original inequality:

5 + 6(1/3) <? 7 The ? shows we're checking; we're not sure if it is <.

5 + 2 <? 7 If m = 1/3, we get 7, so m must be < 1/3.

It checks.
 
Top