One of the factors of x2−2x−15 is _____.
x+3
The given expression is
x2−2x−15
We have to split the middle term in such a way the sum is -2 and product is -15 , which can be done in following way
=x2−5x+3x−15=x(x−5)+3(x−5)
=(x+3)(x−5)
So, x+3 is one of the factors of the given expression.