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Can someone please help me I don't get this at all

Can someone please help me I don't get this at all-example-1
User Mfperzel
by
7.4k points

1 Answer

7 votes

It might help to replace m with some positive number. Let's say m = 5

So everywhere you see an 'm', in an inequality or a graph, replace it with 5. You can pick any other positive number if you prefer.

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Inequality a.

x/m < -1

x/5 < -1 ... replace m with 5

x < -5 ... multiply both sides by 5

The graph will have an open circle at -5 and shading to the left

This describes graph C after you replace m with 5.

Note: if m = 5, then -m = -5.

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

Inequality b.

x/m > 1

x/5 > 1

x > 5

We'll have an open circle at 5 with shading to the right. This describes graph A.

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

Inequality c.

x/m < 1

x/5 < 1

x < 5

This describes graph B since it has an open circle at 5 and shading to the left.

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

Inequality d.

-x/m < 1

-x/5 < 1

x > -5 .... inequality sign flips when we multiply both sides by a negative number

The graph would be graph D because there is an open circle at

-m = -5

and we shade to the right of this open circle.

User Jason Dahl
by
7.2k points