Simplify (5r+6)(5r-6)

$(5 r + 6) (5 r - 6)$

Step 1

Expand $(5 r + 6) (5 r - 6)$ using the FOIL Method.

Apply the distributive property.

$5 r (5 r - 6) + 6 (5 r - 6)$

Apply the distributive property.

$5 r (5 r) + 5 r \cdot - 6 + 6 (5 r - 6)$

Apply the distributive property.

$5 r (5 r) + 5 r \cdot - 6 + 6 (5 r) + 6 \cdot - 6$

Step 2

Simplify and combine like terms.

Simplify each term.

Rewrite using the commutative property of multiplication.

$5 \cdot 5 r \cdot r + 5 r \cdot - 6 + 6 (5 r) + 6 \cdot - 6$

Multiply $r$ by $r$ by adding the exponents.

Move $r$ .

$5 \cdot 5 (r \cdot r) + 5 r \cdot - 6 + 6 (5 r) + 6 \cdot - 6$

Multiply $r$ by $r$ .

$5 \cdot 5 r^{2} + 5 r \cdot - 6 + 6 (5 r) + 6 \cdot - 6$

Multiply $5$ by $5$ .

$25 r^{2} + 5 r \cdot - 6 + 6 (5 r) + 6 \cdot - 6$

Multiply $- 6$ by $5$ .

$25 r^{2} - 30 r + 6 (5 r) + 6 \cdot - 6$

Multiply $5$ by $6$ .

$25 r^{2} - 30 r + 30 r + 6 \cdot - 6$

Multiply $6$ by $- 6$ .

$25 r^{2} - 30 r + 30 r - 36$

Add $- 30 r$ and $30 r$ .

$25 r^{2} + 0 - 36$

Add $25 r^{2}$ and $0$ .

$25 r^{2} - 36$