How do you factor the Trinomal x^2+2x-15=0?

(x + 5)(x - 3) = 0
x = - 5 , x = 3

x^2+2x-15=0

(x + 5)(x - 3) = 0

The idea behind factoring trinomials like this is you want to setup your factors where the multiples of -15 (the third term) add up to 2 (the middle term)... Notice 5 * -3 = -15 and 5 + -3 = 2...

Continuing....
To find the solutions for x:

x + 5 = 0
x = -5
AND
x - 3 = 0
x = 3

ANS: x = -5, 3

x^2 + 2x - 15
= (x + 5)(x - 3)

x^2 + 2x - 15 = 0

Look for factors of -15 that add to 2

+5 & -3 do it

(x + 5)(x - 3)

(x+5)(x-3)=0
x=-5 x=3

first, you find 2 numbers whose product is -15 and sum is 2
that would be 5 and -3, so:
x^2+2x-15=0
(x-3)(x+5)=0
x+5=0 ---> x=-5
x-3=0 ----> x=3
so, x=3 and -5