Question

What is the following product? PLEASE HELP,I'M STRUGGLING SO MUCH!

Answer 1

(x√7 - 3√8 ) (x√7 - 3√8 )

To solve this question you must FOIL (First, Outside, Inside, Last) like so

First:

(x√7 - 3√8 ) (x√7 - 3√8 )

x√7 * x√7

For this you will multiply the numbers/variables on the out side together and separately multiply the values inside the square root together

(x*x)(√7*7)

x²√49

7x²

Outside:

(x√7 - 3√8 ) (x√7 - 3√8 )

x√7 * -3√8

(-3*x)(√7*8)

-3x√56

√56 can be further simplified to: 2√14

Now we have: -3x2√14 ---> -6x√14  

Inside:

(x√7 - 3√8 ) (x√7 - 3√8 )

The process is the exact same as in the "outside"

x√7 * -3√8

(-3*x)(√7*8)

-3x√56

√56 can be further simplified to: 2√14

Now we have: -3x2√14 ---> -6x√14

Last:

(x√7 - 3√8 ) (x√7 - 3√8 )

-3√8 * -3√8

(-3*-3)(√8*√8)

9√64

9*8

72

Now combine all the products of the FOIL together like so...

7x² - 6x√14 - 6x√14 + 72

Combine like terms:

 

7x² - 6x√14 - 6x√14 + 72

^^^When you add together square roots the number inside the radical stays the same, and you combine the numbers/variables attached to the radical on the outside

You selected the correct answer:

7x² -12x√14 + 72  

Hope this helped!

~Just a girl in love with Shawn Mendes