Question

Which binomial is a factor of x2 + 2x − 15?

Answer 1

D. (x − 3)

Explanation:

Break the expression into groups

(x²-3x)+(5x-15)

Factor out x from x²-3x

x(x-3)

Factor out 5 from 5x-15

5(x-3)

x(x-3)+5(x-3)

Factor out the common term (x-3)

(x-3)(x+5)

(x-3) and (x+5) are binomials of x²+2x-15

Answer 2

Explanation:

To factories, we firstly need two brackets, each containing an x .

( x ) ( x )

This creates the x 2 term.

Now we need to get the rest of the terms. To do this, we need two factors of − 15 which will add/subtract to give us + 2

The two factors that do this are

− 3 and 5 , as − 3 + 5 = 2

Answer:( x − 3 ) ( x + 5 )

You can check by expanding it out.