which set of points is in the solution for the system of inequalities: x-y1 and y

Question

which set of points is in the solution for the system of inequalities: x-y>1 and y <2x-1

e.mccormick · Answer

Do you know how to graph an inequality?

anonymous · Answer

no

anonymous · Answer

helping my son with math homework and never seen so many letters in my life

e.mccormick · Answer

You need to graph the line, like it was an =, then find out which side needs to be shaded. http://www.purplemath.com/modules/ineqgrph.htm

anonymous · Answer

the options they give are (-1,-1) or (-2,-1) or (0,1) or (0,-2)

e.mccormick · Answer

Well, if they give points, then what you can do is test them.  Put in the x and y and see if it is true for both equations.

anonymous · Answer

ok I thought so thanks

e.mccormick · Answer

x-y>1
y <2x-1

Yah, so (-1,-1)

$x-y>1\implies -1-(-1)>1 \implies$

$-1+1>1\implies 0 > 1$

Fails the first one, so don't bother with the second, and so on.

e.mccormick · Answer

One of my favorite sites to look things up by topic: http://www.purplemath.com/modules/index.htm A site with amazing examples... but use Googles site search to find things on it: http://regentsprep.org/ (So in Google use site:regentsprep.org some search keys ) And the king of short, topical instuction. https://www.khanacademy.org/ Between those you should be able to learn ahead of your son for most things, and then just ask the remainder here.

e.mccormick · Answer

Look at graping a linear inequality on Regentprep to see why I like it: http://regentsprep.org/Regents/math/ALGEBRA/AE85/GrIneqa.htm That is very easy to read, no junk on it, etc.

anonymous · Answer

thanks

e.mccormick · Answer

np.  have fun!

goformit100 · Answer

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