Thread: Expanding expressions

Im not too sure how to expand these two expressions

1/ (x+2y)(x-2y)2

2/ (1-x)(1+x+x2+x3)


The small numbers r squared and cubed.. not sure how to use it here

Would be good if you can put steps also so i can understand where it comes from..

Thanks

Hi fvaras89

Example
To type square : x^2
To type cube : x^3

or you can learn it here : http://www.mathhelpforum.com/math-he...-tutorial.html

These are hints to help you solve those problems:
1.

2.

Thanks, but im really still not sure what to do.. any more hints?

Hi fvaras89

Can you expand (x+5)^2 ?

Is that how you would expand it?

x^2 + 25x + 25

Hi fvaras89

Almost right. How can you get 25x ?

oh woops hahah..

so would it be x^2 + 25?

Hi fvaras89

Still no.

Do you have a text book that you are working from? I doubt your teacher would give you a task if you're not clear.

I'll use songoku's question:



since the power is 2 it's multiplying itself.

for example

=

now we do the same for this..



now we multiply the first number/letter of the first bracket by the first number/letter of the second bracket



now we multiply the first letter of the first bracket by the second number/ letter



now we multiply the second letter/number by the first number of the second bracket



now the last step... yep that's right, the second number/letter of the first bracket by the second number/letter of the second bracket.



do you get the pattern?

Now put them together



simplify..



now that you've learnt how to do it properly now I tell you the shortcut

when you have 2 brackets multiplying each other and they are IDENTICAL. They have to be identical.

The formula:

can be used.. for example:



x will be "a" and 5 will be "b"

now just substitute:







Was that the same answer as before? it sure was.

Do you understand better now?

i dont understand 6(x+4)
7(3x-9)
x(x+7)
help please
as soon as thanks

WHAT are you asked to do?
Please post problem IN FULL.
I suggest you start your own thread.

Sorry i am new to this...
i am asked to expand these alebraic expressions
5(x+5)
9(8x-9)
x(x+8)
and i really dont understand them so please could you help
thanks Natalie B

Originally Posted by NatalieB

i am asked to expand these alebraic expressions
5(x+5)
9(8x-9)
x(x+8)

Means multiply what's inside brackets by what's outside.
Take 5(x+5)
5 times x = 5x
5 times 5 = 25
So answer is 5x + 25

Let's see you do the other 2: GO Natalie GO

These are hints to help you solve those problems:
1.

2.

Okayy so is this correct ...?
9(8x-9)
9 times 8x=72x
9 times 9 = 81
so its 72x-81

P.S
how do you add the quote in at the top of the page ???