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42 votes
42 votes
X^2 - 3x - 28 factor compleatly

User Eray
by
2.3k points

2 Answers

9 votes
9 votes

Answer:

(x - 7)(x + 4)

Explanation:

To find the factors, you just need to ask yourself the question: Which two numbers multiply to -28 but add to -3?

Simple guess-and-check will lead you to the numbers -7 and 4.

-7 x 4 = -28

-7 + 4 = -3

These numbers will make up the factored equation.

x² - 3x - 28

(x - 7)(x + 4)

You can check your answer by re-expanding the factored expression. This is done by multiplying each term in the first parentheses by each term in the second parentheses.

(x - 7)(x + 4) ----> x² - 7x + 4x - 28 ----> x² - 3x - 28

User Caillou
by
2.6k points
9 votes
9 votes

Answer:

Explanation:

x² - 3x - 28

What factors multiply to -28 and add to -3?

-7 and 4.

(x - 7) (x + 4)

User Sevenseacat
by
3.4k points