How do you factor $y = x^{2} - 2 x - 15$ $y=x^2 - 2x - 15$ ?

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How do you factor $y = x^{2} - 2 x - 15$ $y=x^2 - 2x - 15$ ?

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Answer 1 · 2018-05-28T18:15:27

$y = (x - 5) (x + 3)$ $y=(x-5)(x+3)$

Explanation:

$the factors of - 15 which sum to - 2 are - 5 and + 3$ $"the factors of - 15 which sum to - 2 are - 5 and + 3"$

$y = (x - 5) (x + 3)$ $y=(x-5)(x+3)$

Answer 2 · 2018-05-28T18:17:04

$(x - 5) (x + 3)$ $(x-5)(x+3)$

Explanation:

First, find two numbers that have a sum of -2 (the second term) and have a product of -15 (the third term)
Multiples of 15:
1 | 15
3 | 5
$- 5 \cdot 3 = - 15$ $-5 * 3 = -15$ and $- 5 + 3 = - 2$ $-5 + 3 = -2$
Use this to "split the middle" of the polynomial
$x^{2} - 5 x + 3 x - 15$ $x^2 - 5x + 3x - 15$
Factor
$x (x - 5) + 3 (x - 5)$ $x(x-5) + 3(x-5)$
$(x - 5) (x + 3)$ $(x-5)(x+3)$

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How do you factor $y = x^{2} - 2 x - 15$ $y=x^2 - 2x - 15$ ?

2 Answers

Explanation:

Explanation:

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