Write in Standard Form (5x+4)(5x-4)=0

$(5 x + 4) (5 x - 4) = 0$

Step 1

To write a polynomial in standard form, simplify and then arrange the terms in descending order.

$a x^{2} + b x + c = 0$

Step 2

Expand $(5 x + 4) (5 x - 4)$ using the FOIL Method.

Apply the distributive property.

$5 x (5 x - 4) + 4 (5 x - 4) = 0$

Apply the distributive property.

$5 x (5 x) + 5 x \cdot - 4 + 4 (5 x - 4) = 0$

Apply the distributive property.

$5 x (5 x) + 5 x \cdot - 4 + 4 (5 x) + 4 \cdot - 4 = 0$

Step 3

Simplify terms.

Combine the opposite terms in $5 x (5 x) + 5 x \cdot - 4 + 4 (5 x) + 4 \cdot - 4$ .

Reorder the factors in the terms $5 x \cdot - 4$ and $4 (5 x)$ .

$5 x (5 x) - 4 \cdot (5 x) + 4 \cdot (5 x) + 4 \cdot - 4 = 0$

Add $- 4 \cdot 5 x$ and $4 \cdot 5 x$ .

$5 x (5 x) + 0 + 4 \cdot - 4 = 0$

Add $5 x (5 x)$ and $0$ .

$5 x (5 x) + 4 \cdot - 4 = 0$

Simplify each term.

Rewrite using the commutative property of multiplication.

$5 \cdot (5 x \cdot x) + 4 \cdot - 4 = 0$

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

Move $x$ .

$5 \cdot (5 (x \cdot x)) + 4 \cdot - 4 = 0$

Multiply $x$ by $x$ .

$5 \cdot (5 x^{2}) + 4 \cdot - 4 = 0$

Multiply $5$ by $5$ .

$25 x^{2} + 4 \cdot - 4 = 0$

Multiply $4$ by $- 4$ .

$25 x^{2} - 16 = 0$

Step 4