Chapter 7: Q. 86 (page 832)

In the following exercises, factor each trinomial of the form $x^{2} + b x + c$
$r^{2} - 2 r - 8$

Short Answer

Expert verified

The factorization of $r^{2} - 2 r - 8$ is $(r + 2) (r - 4)$

Step by step solution

step 1. Given information

given expression is $r^{2} - 2 r - 8$

Step 2. Find the last terms of the binomials

Factor out the expression:

Factors of -8	Sum of factors
2,(-4)	2+(-4)= -2
1,(-8)	1+(-8)= -7

step 3. Factorization

Use $2$ and $- 4$ as the last terms of the binomials

$r^{2} - 2 r - 8 = (r + 2) (r - 4)$

Step 4. Check

$(r + 2) (r - 4) = r^{2} + 2 r - 4 r - 8 = r^{2} - 2 r - 8$

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In the following exercises, factor each trinomial of the form $x^{2} + b x + c$
$r^{2} - 2 r - 8$

Short Answer

Step by step solution

step 1. Given information

Step 2. Find the last terms of the binomials

step 3. Factorization

Step 4. Check

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In the following exercises, factor each trinomial of the formx2+bx+cr2-2r-8

Short Answer

Step by step solution

step 1. Given information

Step 2. Find the last terms of the binomials

step 3. Factorization

Step 4. Check

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Math Textbooks

Theoretical and Mathematical Physics

Mechanics Maths

Statistics

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Study anywhere. Anytime. Across all devices.

In the following exercises, factor each trinomial of the form $x^{2} + b x + c$
$r^{2} - 2 r - 8$