[F]hi i need help on solving a algebra problem the problem is (4x-y)(4x+y) YOU HAVE TO SIMPLIFY IT..

Surely you have notes on this, do you not?

Do you know how to simplify it?

Guess it can't hurt, but here's how you simplify it like:

To simplify a (x-y)(x+y) type formula is:
x^2 - y^2

So to apply that you can simply square the first, then square the last and put a minus in. Simplified, it would be 16x^2 - y^2

Here's how - it'll look like a lot, but just follow along and you'll get it. You need to multiply each thing within the brackets with every number that's after it. So expanded it's:

= (4x * 4x) + (4x * y) + (-y * 4X) + (-y * y)
= 16x^2 + 4xy - 4xy - y^2

The 4xy's cancel each other out:

16x^2 - y^2

Hope that clears anything up.

Quote:

---

Originally Posted by SBowman

Guess it can't hurt, but here's how you simplify it like:

To simplify a (x-y)(x+y) type formula is:
x^2 - y^2

So to apply that you can simply square the first, then square the last and put a minus in. Simplified, it would be 16x^2 - y^2

Here's how - it'll look like alot, but just follow along and you'll get it. You need to multiply each thing within the brackets with every number that's after it. So expanded it's:

= (4x * 4x) + (4x * y) + (-y * 4X) + (-y * y)
= 16x^2 + 4xy - 4xy - y^2

The 4xy's cancel each other out:

16x^2 - y^2

Hope that clears anything up.

---

but why can't it solve the x and the y

Quote:

---

Originally Posted by chris_daughtry9

but why can't it solve the x and the y

---

You only have one equation, but two unknowns. There is an infinite number of solutions to this equation. For example, pick a number (any number) for x and then solve for y. Then, pick another number for x and solve for y. You can do this all day. If you had another independent equation, you could solve the pair for one x and one y.

(x - 2)(x + 3)
(x - 3)(x - 2)

3^3x3^4

Rewrite the second equation in the linear system in terms of y. -6x+7y=252 -6x+y=0 y=

*****hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh hhhhhhhhhhhhh

(4x-y)(4x+y)
use the distributive property (FOIL)
4 times 4=16 then you have two x's so it would be 16x^2 then 4x times y which is 4xy. Then from 4xy, you subtract 4xy (since -4xy is inside) then subtract -y so the answer would be 16x^2-y.
This's what I mean:
FOIL: (4x-y)(4x+y)
4x times 4x=16x^2
4x times y =4xy-4xy=0
So it would be 16x^2+0-y
Cancel out the 0 and you get 16x^2-y
I'm really good at math and hope this helps!

I forgot there's 2 y's. The real answer really is 16x^2-y^2