What is the standard form of y=(x - 8) (x + 10) ?

1 Answer
Jul 23, 2016

Check out the explanation.

Explanation:

I would highly recommend using the FOIL method, a mnemonic device that I was taught in my Algebra class. It's simple and very easy to learn and memorize.

So first, let's start off with the equation:

y=(x-8)(x+10)

Using the FOIL method, I will:

  • Multiply the x in the first set of parenthesis by the x in the second set of parenthesis

x^2

  • Multiply the x in the first set of parenthesis by the 10 in the second set of parenthesis

+10x

  • Multiply the -8 in the first set of parenthesis by the x in the second set of parenthesis

-8x

  • Multiply the -8 in the first set of parenthesis by the 10 in the second set of parenthesis.

-80

Now let's combine them all together into one equation:

y=x^2+10x-8x-80

And let's simplify that equation by combining like terms (in this case it's the two numbers that share x as a variable, 10x and -8x). To combine them, all I did was subtract 10x and -8x:

  • y=x^2+2x-80

And there's your answer!

Edit: and here's a picture of the FOIL method.

https://en.wikipedia.orghttps://en.wikipedia.org