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Find the product of (x + 5)(x − 5).

x2 − 10x + 25
x2 + 10x + 25
x2 − 25
x2 + 25

User Hozefa
by
8.2k points

2 Answers

3 votes

Answer: x^2 - 25


Step-by-step explanation:

Here is a tip/ shortcut to multiplying binomials in the (a + b)(a - b) format.

The only things you have to look for is the factor of a * a and the factor of b * b.

The reason being, a * -b and b * a cancel each other out no matter what.

For example

1. (x + 5)(x - 5) Multiply
x_(1) by
x_(2)

x * x =
x^(2)

2. (x + 5)(x - 5) Multiply
x_(1) by -5 in the second binomial

x * -5 = -5x

3. (x + 5)(x - 5) Multiply 5 in the first binomial to
x_(2)

5 * x = 5x

4. (x + 5)(x - 5) Multiply 5 in the first binomial to -5 in the second binomial

5 * -5 = -25

5. Now that you have all of your answers, write your equation, in order, to look like this.


x^(2) - 5x + 5x - 25

6. -5x and 5x cancel each other out when combining like terms so you're left with.


x^(2) - 25


In the end, steps 2, 3, 5, and 6. can be taken out by doing this.

Just multiply
x_(1) by
x_(2) to get
x^(2)

Then just multiply 5 in the first binomial to -5 in the second binomial to get -25

Then write your answer.


x^(2) - 25


This works because there is no need for steps 2,3,5, and 6 since they lead to the same outcome from doing steps 1 and 4.




User Cristiano Bombazar
by
7.7k points
6 votes
x^2 -25
All I did was divide both and I got the answer.
User Yarissa
by
8.9k points