Simplify (a-7)(a+7)

$(a - 7) (a + 7)$

Step 1

Expand $(a - 7) (a + 7)$ using the FOIL Method.

Apply the distributive property.

$a (a + 7) - 7 (a + 7)$

Apply the distributive property.

$a \cdot a + a \cdot 7 - 7 (a + 7)$

Apply the distributive property.

$a \cdot a + a \cdot 7 - 7 a - 7 \cdot 7$

Step 2

Simplify terms.

Combine the opposite terms in $a \cdot a + a \cdot 7 - 7 a - 7 \cdot 7$ .

Reorder the factors in the terms $a \cdot 7$ and $- 7 a$ .

$a \cdot a + 7 a - 7 a - 7 \cdot 7$

Subtract $7 a$ from $7 a$ .

$a \cdot a + 0 - 7 \cdot 7$

Add $a \cdot a$ and $0$ .

$a \cdot a - 7 \cdot 7$

Simplify each term.

Multiply $a$ by $a$ .

$a^{2} - 7 \cdot 7$

Multiply $- 7$ by $7$ .

$a^{2} - 49$