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Let us look at an example. Here is an inequality: 3 is greater than 2.

We write this as: 3 > 2.

Now let us divide both numbers by a negative number. Let us divide by -1 to keep things as simple as possible.

3/-1 = -3

2/-1 = -2

So now the sign of the inequality must be reversed:

-3 < -2.

-3 is smaller than -2 and so the sign was reversed to show this. This holds true for any example we can think of.

Why is this so?

If we were to divide two numbers by a positive number then we would not need to change the sign of the inequality. 4 > 2. (divide by 2) 2 > 1.

However, when we divide a positive number by a negative the result is always negative. A number that was higher when positive will be lower when negative.

Think of a number as representing the distance from 0.

4 is further away from 0 than 3 is. When the distance is greater in a positive way then the number is larger. However when the difference is greater in a negative way, such as with -4 and -3 (-4 is further away from 0) then the number is smaller.

This is what happens when we divide by a negative number and so the inequality sign must be reversed to show this.

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Why must you flip the inequality symbol when you divide by a negative number?

For the same reason you must flip it when you multiply by a negative number. An example should suffice. 2 &lt; 3 If you multiply by -1, without switching the sign, you get: -2 &lt; -3, which is wrong. Actually, -2 &gt; -3. Look at a number line if you are not sure about this - numbers to the left are less than numbers further to the right. Dividing by a negative number is the same as multiplying by the reciprocal, which in this case is also negative. These signs are strictly the "Greater than" and "Less than" signs. The inequality sign is an = with a / stroke through it. If you divide an inequality by -1 it remains an inequality.


When you multiply both sides of any inequality by a negative number you need to the inequality symbol?

When an Inequality expression is multiplied (or divided) by a negative number then the Inequality sign is reversed. Example : -9x &lt; 18 : -x &lt; 2 : x &gt; -2........as both sides have been multiplied by -1.


Solve the inequality negative 3p is greater than 105?

-3p &gt; 105 divide both sides by -3 and remember that when multiplying or dividing by a negative number, you reverse the sense of the inequality: p &lt; -35 To check to make sure the answer makes sense, select a value of p that is less than -35. For example, -100: (-3)(-100) &gt; 105 300 &gt; 105 which is true.


Why it is necessary to reverse the inequality symbol when multiplying both side of an inequality by a negative number?

You need to reverse the inequality symbol when multiplying both sides of an inequality by a negative number because you are changing the sign of both sides of the equation. Since inequality, such as "less than", means "to the left of" on the number line (where left is minus and right is plus) then a number that is less than another will be greater than the other if the signs were reversed. Example: 3 is less than 4, but -3 is greater than -4.


What is the effect of multiplying both sides of an inequality by a negative number?

It changes the direction of the inequality.

Related Questions

Why do you flip the inequality sign when dividing by a negative?

When you divide or multiply both sides of an inequality by a negative number, the order of the values changes, which can reverse the relationship between them. For example, if ( a &lt; b ) and you multiply both sides by -1, the inequality becomes ( -a &gt; -b ). This flip is necessary to maintain the truth of the statement, ensuring that the inequality reflects the correct relationship after the operation. Thus, it's a mathematical rule that helps preserve the validity of the inequality.


When you divide or multiply an inequality by a negative number does it effect the inequality sign?

Yes, when you divide or multiply an inequality by a negative number, you must reverse the inequality sign. For example, if ( a &lt; b ) and you multiply both sides by a negative number ( -c ), the inequality becomes ( -ac &gt; -bc ). This change is necessary to maintain the truth of the inequality.


Why do we flip the inequality symbol when multiplying or dividing by a negative number.?

We flip the inequality symbol when multiplying or dividing by a negative number because it preserves the logical relationship between the quantities involved. For example, if ( a &lt; b ) and we multiply both sides by a negative number, the direction of their relationship changes; thus, ( -a &gt; -b ). This is due to the nature of the number line, where multiplying or dividing by a negative number reverses the order of the numbers. Therefore, flipping the symbol ensures that the inequality remains true.


What happens to the inequality sign when you divide by a negative integer?

When you divide or multiply both sides of an inequality by a negative integer, the inequality sign must be reversed. For example, if you have the inequality (a &lt; b) and you divide both sides by a negative number, the resulting inequality will be (a / (-n) &gt; b / (-n)), where (n) is a positive integer. This reversal is necessary to maintain the truth of the inequality.


What happens to the inequality when it is multiplied by a negative number?

The inequality is "flipped" when multiplied by a negative number. For example, if x &gt; y and a is a negative number, then ax &lt; ay.


Why does the inequality sign flip when both sides of an inequality are multiplied or divided by a negative number Does this happen with equations Explain.?

The inequality sign flips when both sides of an inequality are multiplied or divided by a negative number because the direction of the relationship between the two values reverses. For example, if ( a &lt; b ) and we multiply both sides by -1, the inequality becomes ( -a &gt; -b ) since multiplying by a negative number changes the order of the values. This does not happen with equations because equations represent equality; multiplying or dividing both sides by a negative number does not change their equality.


How the solution for an inequality is different from the solution for a equality?

The main difference is that if you multiply or divide by a negative number, you need to simultaneously invert the inequality - for example, a less-than sign becomes a greater-than sign. Example: -2x &lt; 15 Multiplying by -1/2 (equivalent to dividing by -2): x &gt; 7.5


When should the inequality sign be flipped?

when you divide the inequality by a negative number, for example -2x &gt; 50 then x &lt; -25


What must you do when you multiply or divide each side of an inequality by a negative number?

When you multiply or divide each side of an inequality by a negative number, you must reverse the direction of the inequality sign. For example, if you have ( a &lt; b ) and you multiply both sides by a negative number, the inequality changes to ( -a &gt; -b ). This reversal is crucial to maintain the correct relationship between the two sides of the inequality.


Why must you flip the inequality symbol when you divide by a negative number?

For the same reason you must flip it when you multiply by a negative number. An example should suffice. 2 &lt; 3 If you multiply by -1, without switching the sign, you get: -2 &lt; -3, which is wrong. Actually, -2 &gt; -3. Look at a number line if you are not sure about this - numbers to the left are less than numbers further to the right. Dividing by a negative number is the same as multiplying by the reciprocal, which in this case is also negative. These signs are strictly the "Greater than" and "Less than" signs. The inequality sign is an = with a / stroke through it. If you divide an inequality by -1 it remains an inequality.


When you multiply both sides of any inequality by a negative number you need to the inequality symbol?

When an Inequality expression is multiplied (or divided) by a negative number then the Inequality sign is reversed. Example : -9x &lt; 18 : -x &lt; 2 : x &gt; -2........as both sides have been multiplied by -1.


Solve the inequality negative 3p is greater than 105?

-3p &gt; 105 divide both sides by -3 and remember that when multiplying or dividing by a negative number, you reverse the sense of the inequality: p &lt; -35 To check to make sure the answer makes sense, select a value of p that is less than -35. For example, -100: (-3)(-100) &gt; 105 300 &gt; 105 which is true.