# How do you factor x^2 + 3x - 10?

Jul 23, 2015

$\left(x + 5\right) \left(x - 2\right)$

#### Explanation:

$S = - 3 , P = - 10$

Two numbers whose product is 10: (1, 10) or (2, 5).

The sign of Sum goes to that which the greater modulus.

The sign of Product (-) shows reverse signs.

$x = - 10 \mathmr{and} x = + 1 \setminus R i g h t a r r o w S = - 9$

$x = - 5 \mathmr{and} x = + 2$

Jul 23, 2015

Factor$y = {x}^{2} + 3 x - 10$

y = (x - 2)(x + 5)

#### Explanation:

Y = x^2 + 3x - 10.
Find 2 numbers knowing sum (3) and product (-10).
Factor pairs of (-10) -> (-1, 10)(-2, 5). This sum is 3 = b. The 2 numbers are: -2 and 5.
y = (x - 2)(x + 5).

Jul 23, 2015

$\left(x + 5\right) \left(x - 2\right)$