systems of inequalities
SS?
??
y>−2 x+y≤4
Do you know what to do first?
plot
Good good. Then what?
i dont know how to plot y>-2
Do you know the difference between less than and less than or equal to?
yes
y is greater that -2
Let me rephrase that. Do you know the difference between the lines?
yes the greater than or equal to? If its greater than or equal to/ less than or equal to it has to be a solid line Right?
That is correct.
And what about the normal greater than?
dashed line
Correct again.
So y>-2 is a dashed line, we know that so far. Where on the grid would it go?
im not sure
-2 would be the slope?
That wouldn't be correct because it's not in slope-intercept.
it would be the y intercept?
Yes. Or in other words, where the line is on the grid.
oh there wouldnt be a slope
Yes.
so nowi shade the top because > = greater than = top/right side?
That is correct.
ok thats where i get confused, i have another example where it says y> x-2 but for that i would shade left side, why is that?
Let me graph that real quick.
I believe why that is is because there's an "x" in the problem.
In the original y>-2, there's no "x".
But in this problem/inequality, there's an "x", so that would cause the shading to switch to the left side.
now im not suere how to graph the second equation
It would still be the same line, just shaded on the left side instead of the right.
what
4 is the y-intercept in the second equation
im confused?
|dw:1629828181112:dw| Please excuse my poor drawing skills. As FexrlessRxby was explaining, one way to solve this problem would be to plot the lines (as I tried to do) and then to shade the regions of the graph, based on the sign of the inequality (shade above and to the right for "greater-than"; shade below and to the left for "less-than") The portion where the shading overlaps would be the solution to the system.
And I should shade the same for this x+y≤4
My mistake, I graphed y >= 2, instead of y > -2, as the question asks (also, the line would be dotted, not solid, for a > sign, as opposed to >=. The drawing still illustrates the idea, even though I got the number wrong. The blue line and shading represents the region y >= 2 and the green line and shading represents the region x+y <= 4
how did u graph x+y≤4
Apologies, my drawing was not very good. Please refer to this diagram made using Desmos graphing calculator for a clearer picture. x + y ≤ 4 can also be rewritten as y ≤ -x + 4, if that makes it easier to visualize. The graph would be the line y = -x + 4, with shading underneath the line, since the symbol is "≤", signifying "less than", or below the line
where did you get the - in y ≤ -x + 4
oh i forgot about that
but the full question was Which ordered pair is a solution to the system of inequalities? (1, 3) (1, 5) (0, −4) (−2, −3) doesn't that mean which of these options would be in the double shaded region
That's right, you would want to find out which of the points listed falls within the double-shaded region, meaning it satisfies both of the inequalities in the system
i was learning about this today
so (1,3)
Thank you
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