## Emilyggarza 2 years ago I NEED HELP!!!!!!! DETERMINE WHETHER THE TEST POINT IS A SOLUTION TO THE SYSTEM OF LINEAR INEQUALITIES ( 1, -2) x - 2 y > 3 2x + y < 3

1. matricked

yes

2. Emilyggarza

can you help me?

3. tkhunny

You're not even going to show us that you tried? This is an exersize in three things, Substitution, Manipulation, and Notation. We have a point: (1,-2) The first thing we need is a Notation Test. The notation (1,-2) often means an ordered pair of x- and y-values. (1,-2) MEANS x = 1 and y = -2 We have two inequalities x - 2 y > 3 2x + y < 3 Now, it's time for substitution. We have x's and y's in these inequalities. We must subsitute the known values - known only if we understood the notation (1,-2) SUBSTITUTION x - 2 y > 3 2x + y < 3 or 1 - 2 (-2) > 3 2(1) + (-2) < 3 You must follow this, or we cannot get to the next step. MANIPULATION (a textbook might say, "after a little algebra") 1 - 2 (-2) > 3 2(1) + (-2) < 3 Resolve Parentheses 1 + 4 > 3 2 - 2 < 3 Addition 5 > 3 0 < 3 That's it. Now, we need to understand what we have done. We want to know if the point (1,-2) works in the two inequalities. After substituting the values, we have found an obvious result. 5 > 3 - which is true and 0 < 3 - which is true. If we understand the notation, "<" and ">", we will see that these raltionships are good and we are done with the problem. The given point DID prove appropriate for BOTH inequalities. The given point IS a solution to the SYSTEM of inequalities. Note: Had we achieved 0 > 3 or 10 < -5, we would have laughed at the result, because it is obviuosly false, and conclude that the given point is NOT a solution to the System. What do you think? Are we getting any closer? You will have to show some work if you are to get this in your head. I understand it takes a little courage.

4. Emilyggarza

thank you i honestly didn't know how you gotten 1+4 > 3 but when you shown me step by step it made since because you 1 then you add 2+2=4 then that answer was 1+4> 3 2 (1) + (-2) < 3 then i said how did you get that then you explain it step by step 2 the 2- -2 I still dont know how you got the 2 -2 ? is it because there the same.

5. tkhunny

2 + (-2) = 2 - 2 2 - (-2) = 2 + 2 It is rather awkward notation. Youcan think about multiplicayion rules or direction on a number line. Taht may help, but you may just need to get used to it.