SOLUTION: 2x-y (less than or equal to) 4 x+2y (greater than or equal to) 6 I need to solve both these inequalities to find the correct solution set out of two possible sets. Thanks.

Algebra ->  Inequalities -> SOLUTION: 2x-y (less than or equal to) 4 x+2y (greater than or equal to) 6 I need to solve both these inequalities to find the correct solution set out of two possible sets. Thanks.      Log On


   



Question 1010660: 2x-y (less than or equal to) 4
x+2y (greater than or equal to) 6
I need to solve both these inequalities to find the correct solution set out of two possible sets. Thanks.

Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
2x-y%3C=4 includes the line with equation 2x-y=4 and half of the x-y plane to one side of that line.
To graph that lien we only need to points.
system%28x=0%2C2x-y=4%29-->system%28x=0%2C-y=4%29-->system%28x=0%2Cy=-4%29 ,
so point (0,-4) belongs to the line with equation 2x-y=4 .
system%28y=0%2C2x-y=4%29-->system%28y=0%2C2x=4%29-->system%28y=0%2Cx=2%29 ,
so point (2,0) belongs to the line with equation 2x-y=4 .
With those two points we can graph line 2x-y=4 as
graph%28300%2C300%2C-5%2C5%2C-5%2C5%2C2x-4%29 .
Since point (0,0) , the origin, satisfies 2x-y%3C=4 ,
because 2%2A0-0=0%3C4 ,
the half of the x-y plane that is the graph of 2x-y%3C=4 is
graph%28300%2C300%2C-5%2C5%2C-5%2C5%2C2x-y%3C=4%29 , the half of the x-y plane that contains the origin.
We can do the same for x%2B2y%3E=6 :
system%28x=0%2Cx%2B2y=6%29-->system%28x=0%2C2y=6%29-->system%28x=0%2Cy=3%29 ,
so point (0,3) belongs to the line with equation x%2B2y=6 .
system%28y=0%2Cx%2B2y=6%29-->system%28y=0%2Cx=6%29- ,
so point (6,0) belongs to the line with equation x%2B2y=6 .
With those two points we can graph line x%2B2y=6 as
graph%28300%2C300%2C-2%2C8%2C-5%2C5%2C-0.5x%2B3%29 .
Since point (0,0) , the origin, does not satisfy x%2B2y%3E=6 ,
because 0%2B2%2A0=0%3C6 ,
the half of the x-y plane that is the graph of 2x-y%3C=4 is
graph%28300%2C300%2C-2%2C8%2C-5%2C5%2Cx%2B2y%3E=6%29 , the half of the x-y plane that does not contain the origin.
So the solution to system%282x-y%3C=4%2Cx%2B2y%3E=6%29 is graphed as the shaded area below.