This weak we reviewed greater than and less than problems. Well, part of it was review. First, we learned about the signs, greater than, less than( review ), but than we learned about greater than or equal to( which means the number can be greater than the number or equal to it), less than or equal to( which means the number can be less than or equal to), equals to, and doesn't equal to. We all know how to identify which number is greater than or less than another number. But now the problems are about finding out what a variable can be. Here's an example of one of those problems: 2x+7<39. You just do the problem like it's an equation. So you subtract 7 from both sides.  Now the problem looks like this: 2x<32. Now you divide both sides by two, to get x by itself. So you now have x<16. Another problem is: 10>2x>6. Now you divide all sides by 2, and you get 5>x>3. In English, that means x is less than 5, but more than 3.

There was also something else that was new to us. They are called "and" or "or" problems. So what would you do if you saw a problem that looked like this: 2x<12 or 3x>30. Well, it's quite simple. First you separate each problem and do the problem. So, if I've taught you well, you should have gotten x<6 or x>10. So what does that "or" mean? It just means your answer can be any number less than 6 or is greater than 10. It can be 11, 67, 2, -98. But it can't be 6, 7, 8 or 9( Remember, I said anything less than 6, not 6, or anything greater than 10, not 10). Now let's do an "and" problem: 4x>20 and 2x<22. So once again, separate the problem. You should have gotten x>5 and x<11. The "and" just means any number that follows both rules, not just one. So the answer can only be greater than 5, but less than 11. It can be 6, 7, 8, 9 or 10. The rest of the numbers are all incorrect.


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    Author: Vahae O.

    These Math Mondays blogs are about various subjects and problems with math. There are also simple math tricks on different things stated.