Use the Distributive Property to prove that these algebraic expressions are equivalent. Explain your answer in one sentence for each expression and show your work.

Expression 1: (x−5)(x+3)


Expression 2: 2x^2−x^2−2x−20+5


(4 points)

1 answer

To prove that the expressions \( (x−5)(x+3) \) and \( 2x^2−x^2−2x−20+5 \) are equivalent using the Distributive Property, we can expand Expression 1 and simplify Expression 2.

Expression 1:
Using the Distributive Property (also known as FOIL for binomials), we expand \( (x−5)(x+3) \):

\[ (x−5)(x+3) = x^2 + 3x - 5x - 15 = x^2 - 2x - 15 \]

So, \( (x−5)(x+3) \) simplifies to \( x^2 - 2x - 15 \).


Expression 2:
Now we simplify \( 2x^2−x^2−2x−20+5 \):

\[ 2x^2 - x^2 - 2x - 20 + 5 = (2x^2 - x^2) - 2x + (5 - 20) = x^2 - 2x - 15 \]

Thus, \( 2x^2−x^2−2x−20+5 \) simplifies to \( x^2 - 2x - 15 \).


Conclusion:
Since both expressions simplify to \( x^2 - 2x - 15 \), we have shown that \( (x−5)(x+3) \) is equivalent to \( 2x^2−x^2−2x−20+5 \).