TSI Math: Factoring Trinomials

Factor completely.
9n2 + 15n + 4

Intermediate Algebra and FunctionsQuadratic and Other Polynomial Expressions, Equations, and Functions
Mathematics and Statistics AssessmentQuadratic and Other Polynomial Expressions, and Functions
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TSIMathematics and Statistics Assessment
TSI Math
TSI Mathematics
TSI MathIntermediate Algebra and Functions
TSI MathematicsIntermediate Algebra and Functions
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Transcript

00:23

crowd the prankster tricks You're the one who finds plastic

00:26

vomit hilarious on this test the jokester is the expression

00:29

nine in squared plus fifteen in plus four Why Well

00:32

the first and last terms are perfect squares So this

00:35

try No mia leads us to believe it's A perfect

00:37

square Trying amelia makes it easier to factor Check for

00:41

hand buzzers before grabbing onto this form to be a

00:43

perfect square Trying no menial the middle term must be

00:46

twice the product of the square root of the end

00:50

terms In other words it should be two times quantity

00:53

three times two right there equals twelve in So fifteen

00:57

in does not equal twelve ends of the cord Erratic

00:59

isn't actually a perfect square Try no meal Very funny

01:03

So well we could get rid of a immediately Well

01:05

ignore the jokes here A math joke Sorry It's A

01:08

lower standards and treat The expression is just a normal

01:10

expression while to factor a try no meal who's leading

01:13

coefficient isn't one So you gotta find factors of well

01:17

nine times for equal Thirty six And somehow these have

01:20

tto add two fifteen which is the coefficient in the

01:23

middle term Well what those factors while three times twelve

01:26

is thirty six and three plus twelve is fifteen So

01:30

rewrite fifteen n as three n plus twelve in and

01:34

no joke they have the same value so the replacement

01:36

is completely allowable See how that works So that gives

01:39

us nine squared plus fifteen in plus four is our

01:42

starting point Then we've got nine in squared plus three

01:45

and plus twelve in plus for group The first two

01:47

terms in the last two terms and factory g c

01:50

f out of the group and it looks like this

01:52

Nine in squared plus three and that quantity plus twelve

01:55

in plus four So then we got three and pulled

01:58

out here and they got three and plus one plus

02:00

for three in plus one Well the two term share

02:03

of greatest common factor of three and plus one there

02:05

and just factored out from both terms like any other

02:08

G c f and that gets us three end times

02:10

Quantity three and plus one plus four times quantity three

02:13

plus one and that boils down to three and plus

02:16

one times quantity three and plus for the correct factory

02:19

ization then is the quantity Three in plus one times

02:22

quantity three and plus ford and that's it We're done 00:02:25.575 --> [endTime] it See that's the right answer See you later