PSAT 1.10 Math Diagnostic. Which of the following is a factor of the expression?

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potential answer All right so we just tried asking each

of the answer choices if they were a factor of

the polynomial But well none of them answered Totally unhelpful

Thanks guys Tactic number two we figure it out ourselves

We know that if an expression is the factor of

a polynomial any roots of the expression must be routes

of the polynomial And a root of an expression is

where the expression is equal to zero So if we

want to test whether an expression is a factor of

a polynomial we'll have to set it equal to zero

and then solve for x Well after that we can

substitute the value we get into the equation And if

the whole thing ends up peopling zero then the expression

is a factor or route of the polynomial down confusing

and let's Just see it in action Going with option

a x minus two if we set that equal to

zero i e x minus two equals zero We would

add to to both sides and get x equals two

Now we just take our x value and substitute it

into the original equation We get two cubed minus six

times two Squared plus five times two plus twelve which

simplifies to eight minus twenty four plus ten plus well

and that whole jumbled mess comes out tio six Well

whether or not it's a master of disguises six is

no zero so is out We'll try the same thing

with option b x plus one here will set that

equal to zero then subtract one from both sides to

get x equals negative one and we plug in negative

one for ex well naked one cubed minus six times

negative one squared plus five times negative one plus twelve

as we get that all simplifies too negative one minus

six minus five plus twelve which comes out to wait

for it Zero that's the face of a winner We

could do the same for option cnd but since we

already found the one factor that works there's not really

any need go further unless we're really starved for entertainment 00:02:15.53 --> [endTime] and maybe invest in an xbox