Question

Which will result in a perfect square trinomial (3x-5) (-3x-5)?

Answer 1

-9x² + 25

Explanation:

To solve, use FOIL. FOIL:

First

Outside

Inside

Last

Solve "First":

(3x)(-3x) = -9x²

Solve "Outside":

(3x)(-5) = -15x

Solve "Inside":

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

Solve "Last":

(-5)(-5) = +25

Combine like terms:

-9x² - 15x + 15x + 25

-9x² (-15x + 15x) + 25

-9x² + 25

-9x² + 25 is your answer.

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