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Not sure how to approach this question whether to use the factor theorem or to use the synthetic division

Not sure how to approach this question whether to use the factor theorem or to use-example-1
User Peter Host
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1 Answer

22 votes
22 votes

Step-by-step explanation

If x+2 is a factor, we need to equal the factor to zero, isolate x and substitute the value into the function:


x+2=0\text{ --> x=-2}

Plugging in x=-2 into the function:


P(-2)=(-2)^4-2(-2)^2+3m(-2)+64

Computing the powers:


P(-2)=16-2*4-6m+64

Multiplying numbers:


P(-2)=16-8-6m+64

Adding numbers:


P(-2)=72-6m=0

Adding +6m to both sides:


72=6m

Dividing both sides by 6:


(72)/(6)=m

Simplifying:


12=m

In conclusion, the value of m is 12