Find the products of these binomials: (x-3 (x+3) =?

Question

Hmm? I don't get this, like what do I have to do? Can someone explain to me on how to do this? Thanks

Answer 1

For binomials, I learned this little trick when I was in 8th grade. You FOIL it. Foil is:

F: First
O: Outside
I: Inside
L: Last

so with (x-3)(x+3) you would multiply the first ones in the paranthesis together, so the x's. so that would be x^2. then you do the outside ones. so x and 3, which is 3x. Then the insides, which is -3x, and then the last ones, so -3 times 3, which is -9. Then you add them all up. Since you can't add ones without the same ending, it has to be x^2+-3x+3x+-9.

Now, the -3x and the 3x cancel out, so really it is only x^2+-9.

I hope this method works for you!!

Answer 2

First you multiply the two variables, which is x squared, then you multiply the two outside terms, x and + 3, equaling 3x, and add those to the product of the two inside terms x and -3, equaling -3x. The sum of these terms happens to be 0. Next you multiply the two number values -3 and 3 which of course equals -9. Put these terms together in that order and you get
x squared + 0 + (-9)
You may applaud now.

Answer 3

(x-3) (x+3) = ??

This is a case of FOIL (First, Outside, Inside, Last).

Multiply the First two: x and x
This gives you: x^2

Then multiply the Outside 2: x and 3
This gives you: 3x

Then the Inside 2: -3 and x
This gives you: -3x

Then multiply the Last 2: -3 and 3
This gives you -9

Then add all of them together:
x^2 + 3x + (-3x) + (-9)

The 3x and the -3x cancel each other out, leaving:
x^2 - 9

Answer 4

= x (x + 3) - 3 (x + 3)
= x² + 3x - 3x - 9
= x² - 9

Answer 5

follow this: a^2-b^2=(a-b)(a+b)
a=x
b=3
=>(x-3)(x+3)=(x^2-3^2)
=>(x-3)(x+3)=(x^2-9)
x^2-9 is the answer