Example of Distributive Property- Illustrated Guide
What Is the Distributive Property?
The distributive property is one of the most useful algebra concepts you'll encounter. It lets you multiply a single term by each term inside parentheses.
Here's the basic idea:
a(b + c) = ab + ac
That's it. The a gets distributed to both b and c. No magic, no fluff.
Why It Matters
You need this property for:
- Simplifying algebraic expressions
- Solving equations
- Factoring polynomials
- Mental math calculations
Once you see how it works, you'll start using it automatically. Most people already do this in their head without realizing it.
The Distributive Property Explained With Numbers
Let's start with regular numbers before jumping into variables.
Example 1:
3 × (4 + 2) = ?
Method A — Add first, then multiply:
3 × (6) = 18
Method B — Distribute the 3:
(3 × 4) + (3 × 2) = 12 + 6 = 18
Both methods give the same answer. That's the distributive property in action.
Example 2:
5 × (7 + 3)
Distribute: (5 × 7) + (5 × 3) = 35 + 15 = 50
Check: 5 × 10 = 50 ✓
With Variables
The real power shows up when variables enter the picture.
Example 1:
4(x + 3)
Distribute the 4:
(4 × x) + (4 × 3) = 4x + 12
Example 2:
2(3y - 5)
Distribute the 2 to both terms:
(2 × 3y) + (2 × -5) = 6y - 10
Notice the subtraction carries through. The negative sign stays with the 5.
Example 3:
-3(2x + 7)
(-3 × 2x) + (-3 × 7) = -6x - 21
Common Mistakes to Avoid
People mess this up in a few predictable ways:
- Forgetting to multiply the second term: 3(x + 4) ≠ 3x + 4. It equals 3x + 12.
- Dropping the operator: 2(x - 5) = 2x - 10, not 2x + -10. Both are correct, but keep it clean.
- Distributing when you should combine: (x + 2)(x + 3) requires the distributive property twice. See the next section.
Distributing Over Multiple Terms
What if there's more than two terms inside the parentheses?
Example:
2(x + y + 4)
Multiply 2 by every single term:
(2 × x) + (2 × y) + (2 × 4) = 2x + 2y + 8
The same rule applies. Distribute to all terms, no matter how many there are.
FOIL Method vs. Distributive Property
When multiplying two binomials, you're really applying the distributive property twice.
Take (x + 2)(x + 3):
Step 1: Treat (x + 3) as a single unit
x(x + 3) + 2(x + 3)
Step 2: Distribute each term
x² + 3x + 2x + 6
Step 3: Combine like terms
x² + 5x + 6
That's FOIL broken down to its core. FOIL is just a shortcut for the distributive property applied to binomials.
Practical How To: Using the Distributive Property to Solve Equations
Here's where this gets useful in real problems.
Problem: 4(x + 3) = 28
Step 1: Distribute the 4
4x + 12 = 28
Step 2: Isolate the variable
4x = 28 - 12
4x = 16
Step 3: Solve
x = 4
Problem 2: 2(3x - 5) = 16
6x - 10 = 16
6x = 26
x = 26/6 = 13/3 or 4.33...
Distributive Property vs. Other Properties
| Property | Formula | Example |
|---|---|---|
| Commutative | a × b = b × a | 3 × 4 = 4 × 3 |
| Associative | (a × b) × c = a × (b × c) | (2 × 3) × 4 = 2 × (3 × 4) |
| Identity | a × 1 = a | 7 × 1 = 7 |
| Distributive | a(b + c) = ab + ac | 2(3 + 5) = 6 + 10 = 16 |
The distributive property is the only one that breaks down multiplication across addition or subtraction. The others keep terms grouped or rearranged.
Factoring: The Reverse Process
You can run the distributive property backwards to factor expressions.
Instead of expanding 3(x + 4) into 3x + 12, you take 3x + 12 and find the common factor.
Example:
6x + 9
What's common? Both terms are divisible by 3.
3(2x + 3)
That's factoring. You un-distribute by pulling out the greatest common factor.
Example 2:
12y - 8
Common factor: 4
4(3y - 2)
Quick Reference Cheat Sheet
- a(b + c) = ab + ac
- a(b - c) = ab - ac
- -a(b + c) = -ab - ac
- a(b + c + d) = ab + ac + ad
Keep these patterns in mind. Once you recognize the structure, you can apply it instantly to any expression.
Bottom Line
The distributive property isn't complicated. You take one term and multiply it by everything inside the parentheses. That's the whole concept.
Master this, and algebra gets significantly easier. It's the foundation for multiplying polynomials, solving multi-step equations, and factoring. Skip it, and you'll struggle with everything that follows.