Factor the trinomial.

Question

y^2 + 4y − 21

Answer 1

To factor the trinomial y^2 + 4y − 21, we need to find two numbers that multiply to -21 and add up to 4.

The two numbers that satisfy these conditions are 7 and -3, because 7 * -3 = -21 and 7 + -3 = 4.

Now we can rewrite the trinomial by splitting the middle term:

y^2 + 7y - 3y - 21

Now we can factor by grouping:

y(y + 7) - 3(y + 7)

Now we can factor out the common factor of (y + 7):

(y + 7)(y - 3)

Therefore, the factored form of the trinomial y^2 + 4y - 21 is (y + 7)(y - 3).