ShmoopTube
Where Monty Python meets your 10th grade teacher.
Search Thousands of Shmoop Videos
PSAT 1.7 Math Diagnostic 212 Views
Share It!
Description:
PSAT 1.7 Math Diagnostic. What is the value of x?
More Video DetailsTranscript
- 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
Full Transcript
- 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
Up Next
PSAT 1.1 Reading Diagnostic. The main purpose of the first two paragraphs is to...what?
Related Videos
PSAT 2.2 Reading Diagnostic. What is the main rhetorical effect of this phrase in the second paragraph?
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. Which choice most effectively combines the two sentences in the underlined portion?
PSAT 1.5 Writing Diagnostic. How should the underlined portion be changed in the passage, if at all?