SOLUTION: Can you please help me figure out what coordinates would be the solution to the problem? 2x-3y<9 -2x -2x -3y/-3<-2x/-3+9/-3 y>2/3x-3

Algebra ->  Linear-equations -> SOLUTION: Can you please help me figure out what coordinates would be the solution to the problem? 2x-3y<9 -2x -2x -3y/-3<-2x/-3+9/-3 y>2/3x-3       Log On


   



Question 1169129: Can you please help me figure out what coordinates would be the solution to the problem?

2x-3y<9
-2x -2x
-3y/-3<-2x/-3+9/-3
y>2/3x-3
Would the coordinates be (6,-4), (-1,-9), (2,-5), or (-3,-3)

Found 3 solutions by MathLover1, MathTherapy, ikleyn:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

if you have this:
2x-3y%3C9....solve for y
2x-9%3C3y
3y%3E2x-9
y%3E2x%2F3-3
check the coordinates:
(6,-4)
-4%3E%282%2A6%29%2F3-3
-4%3E4-3
-4%3E1=> false; (6,-4) is not the solution to the problem

(-1,-9)
-9%3E%282%2A-1%29%2F3-3
-9%3E-2%2F3-3
-9%3E-11%2F3=> false; (-1,-9) is not the solution to the problem
(2,-5)
-5%3E%282%2A2%29%2F3-3
-5%3E4%2F3-3
-5%3E4%2F3-9%2F3
-5%3E-5%2F3=> false; (2,-5) is not the solution to the problem

(-3,-3)
-3%3E%282%2A-3%29%2F3-3
-3%3E%282%2A-1%29-3
-3%3E-2-3
-3%3E-5=>true; (-3,-3) IS the solution to the problem


Answer by MathTherapy(10555) About Me  (Show Source):
You can put this solution on YOUR website!
Can you please help me figure out what coordinates would be the solution to the problem?

2x-3y<9
-2x -2x
-3y/-3<-2x/-3+9/-3
y>2/3x-3
Would the coordinates be (6,-4), (-1,-9), (2,-5), or (-3,-3)
You DON'T have to solve he inequality for y before checking the coordinate points. 
That's work that's TOTALLY UNNECESSARY! Unless, of course you're requested to solve for y.

2x - 3y < 9 
2(6) - 3(- 4) < 9 ------ Substituting (6, - 4) for (x, y)
12 + 12 < 9
24 < 9 
The above is FALSE, so (6, - 4) is NOT a solution.

2x - 3y < 9 
2(- 1) - 3(- 9) < 9 ------ Substituting (- 1, - 9) for (x, y)
- 2 + 27 < 9
25 < 9 
The above is FALSE, so (- 1, - 9) is NOT a solution. 

2x - 3y < 9 t
2(2) - 3(- 5) < 9 ------ Substituting (2, - 5) for (x, y)
4 + 15 < 9
19 < 9 
The above is FALSE, so (2, - 5) is NOT a solution.

2x - 3y < 9 
2(- 3) - 3(- 3) < 9 ------ Substituting (- 3, - 3) for (x, y)
- 6 + 9 < 9
3 < 9 
The above is TRUE, so (- 3, - 3) IS a solution.

Answer by ikleyn(52851) About Me  (Show Source):
You can put this solution on YOUR website!
.

From the given inequality, you correctly deduced this final inequality


    y > %282%2F3%29x+-+3.    (1)


Geometrically, you draw the straight line y = %282%2F3%29x+-+3,


It divides the coordinate plane in two parts: one part is above this line; the other part is below this line.


The set of solutions to the inequality (1) is the set of all points of the coordinate plane, that are strictly

above the line (excluding points on the line).


So, if you draw the line on the graph paper, which has coordinate grid,

you can easily see which points do belong to the solution set and which points do not.



    


                           Line y = %282%2F3%29x-3



If the problem asks whether the assigned points do belong to the solution set, you always can substitute their coordinates 
into the given inequality and check immediately for these points.

--------------

On solving inequalities in two variables graphically,  look into the lesson
    - Solving systems of inequalities in two unknown graphically in a coordinate plane
in this site.

Learn the method from there.


Happy learning (!)