## Expanding (x-10)(x+10) into Standard Form

The expression (x-10)(x+10) is in factored form. To rewrite it in standard form, we need to expand it using the distributive property (often referred to as FOIL).

**FOIL** stands for **F**irst, **O**uter, **I**nner, **L**ast, which helps us remember the order of multiplication.

**First:**Multiply the first terms of each binomial:**x * x = x²****Outer:**Multiply the outer terms of the binomials:**x * 10 = 10x****Inner:**Multiply the inner terms of the binomials:**-10 * x = -10x****Last:**Multiply the last terms of each binomial:**-10 * 10 = -100**

Now, we have: **x² + 10x - 10x - 100**

Finally, combine the like terms: **x² - 100**

Therefore, the standard form of (x-10)(x+10) is **x² - 100**.

**Important Note:** This expression is a special case called the **difference of squares**. The pattern is **(a-b)(a+b) = a² - b²**.

Understanding this pattern can help you quickly expand similar expressions without going through the full FOIL process.