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PSAT 1.1 Math Diagnostic
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PSAT 1.1 Math Diagnostic. If a rabbit consumes 3 meals a day, how many grams of food will a rabbit consume in 7 days?

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

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PSAT 1.7 Math Diagnostic 212 Views


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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

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