ShmoopTube

Where Monty Python meets your 10th grade teacher.

Search Thousands of Shmoop Videos


PSAT Videos 97 videos

PSAT 1.8 Math Diagnostic
211 Views

PSAT 1.8 Math Diagnostic. What is one value of x?

PSAT 1.38 Math Diagnostic
180 Views

PSAT 1.38 Math Diagnostic. What is f(g(x))?

PSAT 1.37 Math Diagnostic
177 Views

PSAT 1.37 Math Diagnostic. Which of the following forms of the function f(x) would best reveal the number of employees that should be hired to maxi...

See All

PSAT 1.7 Math Diagnostic 212 Views


Share It!


Description:

PSAT 1.7 Math Diagnostic. What is the value of x?


Transcript

00:00

Thank you We sneak and here's your shmoop du jour

00:05

brought to you by hot dogs We hope you'll relish

00:08

this one If four square root of ax equals eight

00:14

Acts minus 24 what's the value of acts and hear

00:17

potential answers all right little fashion algebra but what a

00:21

mess It looks simple enough but once we realize that

00:24

there's a square root on one side not the other

00:27

and that multiplying or adding anything that both sides only

00:30

makes it look more daunting it's almost enough to make

00:32

us throw our hands up in the air give up

00:35

on this problem and distract ourselves instead with a hot

00:37

dog or two But then inspiration strikes You don't even

00:41

have to worry about simplifying this equation in a test

00:44

situation where every seconds precious why not go easy on

00:47

ourselves and take a shortcut here All we have to

00:49

do is plug in the four answer choices one by

00:52

one until we find the one that makes the equation

00:54

true It's quick it's easy and shortcuts go there's Very

00:57

little chance of us getting it wrong So we'll start

01:00

with a a and see if that works well Two

01:03

point two five Lugging that into the equation We get

01:05

four times square to two point two five equals eight

01:09

times two Point two five minutes twenty four we'll square

01:12

in a two point two five one point five times

01:14

for and that six on the right side of the

01:17

equation eight times two point two fives eighteen minutes twenty

01:21

for well that's negative six we don't see any absolute

01:24

value signs around that sucker so we could get rid

01:26

of a what about c five else plugging in this

01:30

time We've got four times square root of five which

01:33

can be simplified more than four square route five equals

01:37

eight times five or forty minus twenty four which is

01:40

sixteen One side still has square root symbol on the

01:43

other dozen Well in this scenario the equal signs a

01:46

big fat liar and ain't see let's try d eight

01:50

unfortunately that same problem here eight is the same as

01:52

four times too so we can rewrite it as two

01:55

square root of two But even still no matter how

01:58

you cut it we're gonna end up with a square

02:00

root symbol on the left side of the equation and

02:02

there won't be one on the right so will bid

02:04

and not so fond farewell to d well the right

02:07

answer is b for the square root of four is

02:09

exactly to which gets rid of that ugly symbol Two

02:12

times Four is eight equals eight tons for or thirty

02:15

two minus twenty four which is also ate and there's

02:17

our true statement Speaking of true statements if he ever

02:20

tried ordering a hot dog with ketchup in the city

02:22

of chicago you will immediately be arrested You don't believe 00:02:25.865 --> [endTime] us Just try it We double hot dog area

Related Videos

PSAT 1.1 Reading Diagnostic
1006 Views

PSAT 1.1 Reading Diagnostic. The main purpose of the first two paragraphs is to...what?

PSAT 2.2 Reading Diagnostic
379 Views

PSAT 2.2 Reading Diagnostic. What is the main rhetorical effect of this phrase in the second paragraph?

PSAT 1.3 Writing Diagnostic
282 Views

PSAT 1.3 Writing Diagnostic. To make the paragraph most logical, sentence 2 in the second paragraph should be placed...where?

PSAT 1.4 Writing Diagnostic
239 Views

PSAT 1.4 Writing Diagnostic. Which choice most effectively combines the two sentences in the underlined portion?

PSAT 1.5 Writing Diagnostic
239 Views

PSAT 1.5 Writing Diagnostic. How should the underlined portion be changed in the passage, if at all?