Write in Standard Form y=(x+1)(x-3)

$y = (x + 1) (x - 3)$

Step 1

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

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

Step 2

Expand $(x + 1) (x - 3)$ using the FOIL Method.

Apply the distributive property.

$y = x (x - 3) + 1 (x - 3)$

Apply the distributive property.

$y = x \cdot x + x \cdot - 3 + 1 (x - 3)$

Apply the distributive property.

$y = x \cdot x + x \cdot - 3 + 1 x + 1 \cdot - 3$

Step 3

Simplify and combine like terms.

Simplify each term.

Multiply $x$ by $x$ .

$y = x^{2} + x \cdot - 3 + 1 x + 1 \cdot - 3$

Move $- 3$ to the left of $x$ .

$y = x^{2} - 3 \cdot x + 1 x + 1 \cdot - 3$

Multiply $x$ by $1$ .

$y = x^{2} - 3 x + x + 1 \cdot - 3$

Multiply $- 3$ by $1$ .

$y = x^{2} - 3 x + x - 3$

Add $- 3 x$ and $x$ .

$y = x^{2} - 2 x - 3$

Step 4