Factorise x2-3x-10

x2 is x squared

X²-3x-10

1) solve this equation:

x²-3x-10=0

x=[3⁺₋√ (9+40) ] / 2 = (3⁺₋7) / 2

We have two solutions:

x₁ = (3-7) / 2=-4/2=-2 ⇒ (x+2)

x₂ = (3+7) = 10/2=5 ⇒ (x-5)

Therefore:

x²-3x-10 = (x+2) (x-5)

X² - 3x - 10 = 0

(x - 5) (x + 2) = 0

x - 5 = 0 ⇒ x = 5

x + 2 = 0 ⇒ x = - 2

(x - 5) (x + 2) = 0

x (x + 2) - 5 (x + 2) = 0

x² + 2x - 5x - 10 = 0

x² - 3x - 10 = 0

x² ⇒ is x * x

Factors of 10 are:

1 x 10

2 x 5

-3 is indicative whether the factors will use a positive or negative sign.

to produce - 3 the factors of 10 will be 2 and - 5.