Simplify (3x+5y)(3x-5y)

$(3 x + 5 y) (3 x - 5 y)$

Step 1

Expand $(3 x + 5 y) (3 x - 5 y)$ using the FOIL Method.

Apply the distributive property.

$3 x (3 x - 5 y) + 5 y (3 x - 5 y)$

Apply the distributive property.

$3 x (3 x) + 3 x (- 5 y) + 5 y (3 x - 5 y)$

Apply the distributive property.

$3 x (3 x) + 3 x (- 5 y) + 5 y (3 x) + 5 y (- 5 y)$

Step 2

Simplify and combine like terms.

Simplify each term.

Rewrite using the commutative property of multiplication.

$3 \cdot 3 x \cdot x + 3 x (- 5 y) + 5 y (3 x) + 5 y (- 5 y)$

Multiply $x$ by $x$ by adding the exponents.

Move $x$ .

$3 \cdot 3 (x \cdot x) + 3 x (- 5 y) + 5 y (3 x) + 5 y (- 5 y)$

Multiply $x$ by $x$ .

$3 \cdot 3 x^{2} + 3 x (- 5 y) + 5 y (3 x) + 5 y (- 5 y)$

Multiply $3$ by $3$ .

$9 x^{2} + 3 x (- 5 y) + 5 y (3 x) + 5 y (- 5 y)$

Rewrite using the commutative property of multiplication.

$9 x^{2} + 3 \cdot - 5 x y + 5 y (3 x) + 5 y (- 5 y)$

Multiply $3$ by $- 5$ .

$9 x^{2} - 15 x y + 5 y (3 x) + 5 y (- 5 y)$

Rewrite using the commutative property of multiplication.

$9 x^{2} - 15 x y + 5 \cdot 3 y x + 5 y (- 5 y)$

Multiply $5$ by $3$ .

$9 x^{2} - 15 x y + 15 y x + 5 y (- 5 y)$

Rewrite using the commutative property of multiplication.

$9 x^{2} - 15 x y + 15 y x + 5 \cdot - 5 y \cdot y$

Multiply $y$ by $y$ by adding the exponents.

Move $y$ .

$9 x^{2} - 15 x y + 15 y x + 5 \cdot - 5 (y \cdot y)$

Multiply $y$ by $y$ .

$9 x^{2} - 15 x y + 15 y x + 5 \cdot - 5 y^{2}$

Multiply $5$ by $- 5$ .

$9 x^{2} - 15 x y + 15 y x - 25 y^{2}$

Add $- 15 x y$ and $15 y x$ .

Move $y$ .

$9 x^{2} - 15 x y + 15 x y - 25 y^{2}$

Add $- 15 x y$ and $15 x y$ .

$9 x^{2} + 0 - 25 y^{2}$

Add $9 x^{2}$ and $0$ .

$9 x^{2} - 25 y^{2}$