Question

Frank is trying to factor He has determined that one factor is (y + 9). What is the other factor?

Answer 1

Final answer is D. (y-3)

Explanation:

Frank is trying to factor
`y^2+6y-27`. He has determined that one factor is (y+9). Now we need to find the other factor.

So let's factor
`y^2+6y-27`

`y^2+6y-27`

`=y^2+9y-3y-27`

`=y(y+9)-3(y+9)`

`=(y-3)(y+9)`

Hence the other factor is (y-3).

Answer 2

Correct choice is D

Explanation:

The quadratic polynomial can be factored as

`(y-y_1)(y-y_2),`

where
`y_1,\ y_2` are roots of the polynomial.

If one of the factors is
`y+9,` then one of the roots is -9.

By the Vieta formulas,

`y_1+y_2=-6,\\ \\y_1\cdot y_2=-27.`

Then

`-9+y_2=-6,\\ \\-9y_2=-27.`

From these equations ou can conclude that
`y_2=3.`