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Does anyone know this? If you do can you please help me?

Does anyone know this? If you do can you please help me?-example-1
User Whywake
by
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1 Answer

6 votes

Answer:

  • -2x > 30
  • x < -15

Explanation:

A product is formed by multiplying the factors. Here, you want the product of -2 and x, so that is indicated as ...

-2x

You want that product greater than 30. The symbol for "greater than" is >, so you have ...

-2x > 30 . . . . the desired inequality

__

The most straightforward way to solve this is to divide by the coefficient of x. Because that is negative, you must reverse the inequality symbol from "greater than" to "less than."

x < 30/(-2)

x < -15 . . . . . . the desired solution

_____

Additional comment

It may not be clear why multiplying or dividing an inequality causes the symbol to be reversed. You can think of it as reflecting the inequality over the point x=0 on the number line. Where larger numbers were on the right, they get reflected to points farther left, so as negative numbers, they are smaller numbers.

Consider ...

1 < 2

-1 > -2

User Maher
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