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How do I solve for question E using the factoring method? p(x)=2/5

How do I solve for question E using the factoring method? p(x)=2/5-example-1
User Alexnavratil
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1 Answer

14 votes
14 votes

Given the function:


p(x)=(-2x+8)/(x^2+6x+8)

You know that:


p(x)=(2)/(5)

Then, you need to substitute that value into the function:


(2)/(5)=(-2x+8)/(x^2+6x+8)

You can multiply the numerator 2 by the denominator of the expression on the right, and the expression in the numerator on the right by the denominator 5:


(2)(x^2+6x+8)=(5)(-2x+8)
2x^2+12x+16=-10x+40

Make the equation equal to zero and add the like terms:


2x^2+12x+16+10x-40=0
2x^2+22x-24=0

Simplify it by dividing both sides by 2:


(2x^2+22x-24)/(2)=(0)/(2)
x^2+11x-12=0

Apply the Factoring Method by finding two numbers whose Sum is 11 and whose Product is -12. These would be 12 and -1. Then:


(x+12)(x-1)=0

Solving for "x", you get:


\begin{gathered} x_1=-12 \\ x_2=1 \end{gathered}

Hence, the answer is:


\begin{gathered} x_1=-12 \\ x_2=1 \end{gathered}

User Srikanta
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