factorise x 2-y2-2y-1
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Answered by
121
x^2-(y^2+2y+1^2)
x^2-(y+1)^2
{x-(y+1)} {x+(y+1)}
(x-y-1)(x+y+1)
x^2-(y+1)^2
{x-(y+1)} {x+(y+1)}
(x-y-1)(x+y+1)
Answered by
55
Taking minus common
x*2-(y*2+2y+1)=0
Now y*2+2y+1 is inform of(a+b)*2=a*2+b*2+2ab
So taking it in identity form
x*2-(y+1)*2=0
It is in form of indentitiy that is
a*2-b*2=a+b(a-b)
Here a=a*2 and b= (y+1)*2
There for
(x+y+1)(x-y-1)=0
So x= -y-1 or x= y+1
x*2-(y*2+2y+1)=0
Now y*2+2y+1 is inform of(a+b)*2=a*2+b*2+2ab
So taking it in identity form
x*2-(y+1)*2=0
It is in form of indentitiy that is
a*2-b*2=a+b(a-b)
Here a=a*2 and b= (y+1)*2
There for
(x+y+1)(x-y-1)=0
So x= -y-1 or x= y+1
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