When rearranging an inequality, when do you switch the sign?
eg
x-1<y
Say I want to isolate x can I do this?
x<y+1
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A Simple Inequality Concept That is Giving Me Trouble
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austin
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Alex,
-x < 2 => x> -2 (multiply or divide by negative sign on both sides will switch the inequality)
-x> -2 => x<2 (same rule)
-x<-2 => x>2 (same rule)
-x > 2 => x < -2 (same rule)
-x < 2 => x> -2 (multiply or divide by negative sign on both sides will switch the inequality)
-x> -2 => x<2 (same rule)
-x<-2 => x>2 (same rule)
-x > 2 => x < -2 (same rule)
-
logitech
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lets see it with some numbers
-4 < -3
4 > 3
AHA sign changed, when we multiply both side with - 1
Or
3 > -7
-3 < 7
Hmmm
-6 < - 4
- 6 + 40 < - 4 + 40
34 < 36
Sign did not change!!!
-6 - 40 < -4 - 40
-46 < - 44
sign did not change
now lets divide this by +2
-23 < - 22
sign did not change, lets try it with -2
23 > 22
AHA sign changed!!
So whenever you multiply or divide by a negative number make sure to change the sign and remember this exercise!
Have Fun!
-4 < -3
4 > 3
AHA sign changed, when we multiply both side with - 1
Or
3 > -7
-3 < 7
Hmmm
-6 < - 4
- 6 + 40 < - 4 + 40
34 < 36
Sign did not change!!!
-6 - 40 < -4 - 40
-46 < - 44
sign did not change
now lets divide this by +2
-23 < - 22
sign did not change, lets try it with -2
23 > 22
AHA sign changed!!
So whenever you multiply or divide by a negative number make sure to change the sign and remember this exercise!
Have Fun!
LGTCH
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