ShmoopTube

00:03

All right sy Maths members Here we go Next up

00:05

Which of the following inequalities is represented by the solution

00:10

set All right so we've got three right there and

00:16

then everything greater than three Well each february we wait

00:20

for the ground hog pop out of his graph and

00:23

create a solution set that predicts how many more math

00:25

questions we have remaining for the year Here he comes

00:28

out of the open hole at x equals three Now

00:31

his shadow falls on all numbers greater than three The

00:35

ground hog has spoken All that remains is for us

00:37

to interpret his statement right We can't immediately eliminate the

00:40

first two inequalities simply because they have less than symbols

00:43

The inequality could flip during the solving process because the

00:47

coefficient of the variables negative in dividing by negative value

00:50

flips the direction of the duck mouth We like the

00:52

ground hog must dig our way out of this one

00:55

So we gotta solve for negative For x plus one

00:57

is less than negative thirteen first Well we're gonna plug

01:01

in chuck here when dividing by negative for flip the

01:03

inequality and we get negative for x plus one is

01:06

less than negative thirteen and then we're going to subtract

01:09

one from both sides Got negative for exes last night

01:11

and they could afford eighteen but then we're going to

01:13

flip the duck mouth here because we're gonna divide both

01:15

sides by yet negative for their so that'll get us

01:18

fourteen over and floor in that same as fourteen over

01:22

for And no this is not what depression rodent meant

01:25

All right let's just solve the second equation before except

01:27

this one's lesson thirteen Well let's see we've got to

01:30

add one to both sides So we get teo negative

01:33

four axes less than fourteen and we're gonna divide both

01:36

sides by negative for and that's flipping the duck mouth

01:38

there So we get x is greater than negative Fourteen

01:42

over four Well that's not right bill solution set toe

01:45

negative for x minus ones Lesson thirteen doesn't match the

01:48

ground hogs prediction either but it's similar enough to axe

01:51

is greater than fourteen over four that were beginning to

01:54

worry We've stumbled on a glitch in the space time

01:57

continuum Alright so quick Avoid repetition by deploying logic The

02:00

inequality for x minus one is greater than thirteen Must

02:03

have the same solution as negative for x plus one

02:07

is less than negative thirteen there like a because all

02:09

the terms have opposite signs and the inequality faces the

02:13

opposite direction We'll just get rid of sea without plugging

02:16

and or chugging The last inequality is for x plus

02:19

one is greater than thirteen must be the one that

02:22

models the ground hogs prediction here right Otherwise the world

02:26

is just too uncertain and on a good place to

02:29

live your day again and again again alright for x

02:31

plus ones great in thirteen so we tracked one from

02:34

both sides for x is greater than twelve And if

02:37

we divide both sides by four and since it's positive

02:39

number we don't have flipped the duck mouth so it

02:41

just gets your axes creator than three What do you

02:44

know The fur ball came through We have for x

02:47

plus ones great in thirteen and math problems to complete

02:50

this year The good news is we've already done three 00:02:53.22 --> [endTime] of them who

Full Transcript