## Shikar23234 3 years ago Simplify: (x - 4)2 x2 - 16 x2 - 8 x2 - 8x + 16 x2 - 16x + 8

1. sam30317

When you have a squard function (or any function raised to an exponent), u need to set it up as: (x-4)(x-4)

2. sam30317

|dw:1339623456630:dw|

3. Shikar23234

So it would be x2 -8?

4. sam30317

Nope. U now need to distribute the x and 4 (multiply) with the terms in the OTHER parenthesis

5. sam30317

(x-4)(x-4)= (x*x) - (4*x) = (x^2-4x) <--- this is only part of it

6. Shikar23234

Oh!!!! So you basically just multiply the x to the other side and then do the same with the 4. So it would be 4 times x then 4 times 4. Right?

7. sam30317

Right!!!

8. sam30317

9. Shikar23234

So i know the 16 goes on the very end so im thinking its C but i dont know how it gets the 8.

10. sam30317

Pay attention to your pos/neg signs when you combine like terms. x^2 -4x-4x+16 ---> Because you have two of the same (-4x), u combine them. -4-4= -8. Do u see??

11. Shikar23234

Sort of. So its basically x - y + (y*y) ?

12. sam30317

Errr, i dont understand that little formula. Im sorry. Let me try another way. 1st, do u see why I have two -4's??

13. Shikar23234

Uhm yea. because its (x-4) and (x-4). So you just put them togeather. x= x2 and -4= -8. Right?

14. sam30317

Hmmm, u're right. But Hopefully u wont confuse yourself with that formula u had before

15. Shikar23234

Well what i dont understand is why you have to multiply it when your just simplifying it.

16. sam30317

Simplify means that you are turning the function/equation into ONE form. Basically, you want to combine all like terms on both sides and reduce it to it's simplest form.

17. Shikar23234

But then what if your multiplying it? For instance 5xy(2x - y). Does that mean you just to the same thing?

18. sam30317

The 1st problem u had above, is not giving us any information. But in it's simplest form, we can find maximums & minimums of a graph, points of intersection, slope. You'll learn about all that stuff later. But you cant find the information you need with it being in the simplest form

19. sam30317

Yes, u do the same thing

20. sam30317

BUT, 5xy is considered ONE term. Dont separate the 5 from x & y

21. Shikar23234

So you just separate the 5xy from the (2x - y) ? Then multiply the 2 together?

22. sam30317

No need to separate anything. A number infront of a parenthesis also means to multiply. Or, to distribute the 1st number with each number on the inside of the parenthesis

23. sam30317

Try 10(9x+3)

24. sam30317

It means that (10*9x) PLUS (10*3).

25. sam30317

|dw:1339625177685:dw|

26. Shikar23234

So it would be 90x+30. Would you need to simplify?

27. sam30317

CORRECT! If it is simplified again, it would go back to its orginal form 10(9x+3)

28. sam30317

Ok, i really suck at explaining! im sorry

29. Shikar23234

Ohhhhhh! I understand now! Thank you!!!!!

30. sam30317

cooool! No problem. Do u get the -8 though? I can draw a pic.

31. Shikar23234

Yea i understand that part now. Seriously though thanks abunch!

32. sam30317