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# really confused by this maths question watch

1. It looks simple enough but i don't understand why you can't just multiply out the denominator so it ends up x^2 - y^2....

2. it makes no sense your mulipication :P
3. (Original post by FlamingSpittoon)
It looks simple enough but i don't understand why you can't just multiply out the denominator so it ends up x^2 - y^2....

You cant multiply like that.
Remember how you multiply our brackets.

(x-y)^2 means (x-y)(x-y)
Now multiply out using FOIL method.
4. (Original post by Aniaa)
it makes no sense your mulipication :P
I thought if something was (x-y)^2 it multiplied out as (x-y)(x+y)... ?
5. (Original post by FlamingSpittoon)
I thought if something was (x-y)^2 it multiplied out as (x-y)(x+y)... ?
No, squaring means (by definiton) multiplying something by itself. x^2 is x*x so (x-y)^2 is (x-y)*(x-y).

I tihnk you may be getting confused with teh difference of 2 squares, it is true that x^2-y^2=(x-y)(x+y) but this is not what you are given here.
6. (Original post by MrHappyChappy)
You cant multiply like that.
Remember how you multiply our brackets.

(x-y)^2 means (x-y)(x-y)
Now multiply out using FOIL method.
what is the FOIL method?
7. (Original post by james22)
No, squaring means (by definiton) multiplying something by itself. x^2 is x*x so (x-y)^2 is (x-y)*(x-y).

I tihnk you may be getting confused with teh difference of 2 squares, it is true that x^2-y^2=(x-y)(x+y) but this is not what you are given here.
ahh okay, thanks.
8. (Original post by Secretnerd123)
what is the FOIL method?

A Method used to multiply out brackets.

Firsts
Outsides
Insides
Lasts

FOIL

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