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### Course: Algebra (all content) > Unit 10

Lesson 7: Special products of binomials- Multiply difference of squares
- Special products of the form (ax+b)(ax-b)
- Squaring binomials of the form (ax+b)²
- Special products of binomials: two variables
- More examples of special products
- Polynomial special products: perfect square
- Squaring a binomial (old)
- Binomial special products review

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# Binomial special products review

A review of the difference of squares pattern (a+b)(a-b)=a^2-b^2, as well as other common patterns encountered while multiplying binomials, such as (a+b)^2=a^2+2ab+b^2.

These types of binomial multiplication problems come up time and time again, so it's good to be familiar with some basic patterns.

The "difference of squares" pattern:

Two other patterns:

### Example 1

**Expand the expression.**

The expression fits the difference of squares pattern:

So our answer is:

But if you don't recognize the pattern, that's okay too. Just multiply the binomials as normal. Over time, you'll learn to see the pattern.

Notice how the "middle terms" cancel.

*Want another example? Check out this video.*

### Example 2

**Expand the expression.**

The expression fits this pattern:

So our answer is:

But if you don't recognize the pattern, that's okay too. Just multiply the binomials as normal. Over time, you'll learn to see the pattern.

*Want another example? Check out this video.*

### Example 3

**Expand this expression.**

The expression fits the difference of squares pattern:

So our answer is:

But if you don't recognize the pattern, that's okay too. Just multiply the binomials as normal. Over time, you'll learn to see the pattern.

Notice how the "middle terms" cancel.

*Want more practice? Check out this intro exercise and this slightly harder exercise.*

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