Question

Determine the factors of x2 − 7x − 10. (5 points) a (x + 2)(x − 5) b Prime c (x − 2)(x + 5) d (x + 10)(x − 1)

Answer 1

For this case we must factor the following expression:

$x ^ 2-7x-10$

To factor, we must find two numbers that when added together give -7 and when multiplied by -10.

It is observed that there are not two whole numbers that comply with the aforementioned.

Thus, the following equation applies:

$x = \frac {-b \pm\sqrt{b ^ 2-4 (a) (c)}} {2 (a)}$

Where:

$a = 1\\b = -7\\c = -10$

We replace:

$x = \frac {- (- 7) \pm \sqrt {(- 7) ^ 2-4 (1) (- 10)}} {2 (1)}\\x = \frac {7 \pm \sqrt {49 + 40}} {2}\\x = \frac {7 \sqrt {89}} {2}$

So, the roots are:

$x_ {1} =\frac {7+ \sqrt {89}} {2}\\x_ {2} =\frac {7- \sqrt {89}} {2}$

Answer:

$x_ {1} =\frac {7+ \sqrt {89}} {2}\\x_ {2} =\frac {7- \sqrt {89}} {2}$