How do I factor
36x^2-100y^2

Question

How do I factor
36x^2-100y^2

anonymous · Answer

$$36x^2-100y^2$$

mathmagician · Answer

(6x-10y)(6x+10y)

anonymous · Answer

its a difference of two squares

$$36x^2 - 100y^2 = (6x + 10y)(6x - 10y)$$

anonymous · Answer

when you multiply out, the (6x*10y) terms cancel each other

anonymous · Answer

that is why it works

anonymous · Answer

(6x)^2 - (10y)^2 

Now We know that
$$a ^{2} - b ^{2} = (a+b)(a-b)$$ 
Therefore we get 
$$(6x+10y)(6x-10y)$$

@eigenschmeigen  got it before me :)

anonymous · Answer

(6x)^2-(10y)^2
a^2-b^2=(a+b)(a-b)
Applying this identity :
=(6x+10y)(6x-10y)
these are the factors

anonymous · Answer

and @mathmagician before me :)

anonymous · Answer

Sorry.  Did nt see @mathmagician  :)

anonymous · Answer

Thanks guys.
I originally got what you all got too but when I checked my answer online, it gave me: 4(3x-5y)(3x+5y) so I thought I did something wrong.

anonymous · Answer

another example would be 

$$25x^2 - 49y^2$$

since $$25x^2 = (5x)^2 \text{  and   } 49y^2 = (7y)^2$$

$$25x^2 - 49y^2 = (5x-7y)(5x+7y)$$

ah ok so it just wanted you to take out four as a factor as well