is (x+y)^2 = x^2+y^2 or x^2+2xy+y^2?

(x + y)² = x² + 2xy + y²

it is x^2+2xy+y^2

(x+Y)^2 = (x+Y) (x+Y) = x^2+xy+xy+y^2 = x^2+2xy+y^2

d ans is


x² + 2xy + y²

(x + y)^2
= (x + y)(x + y)
= x*x + y*x + x*y + y*y
= x^2 + xy + xy + y^2
= x^2 + 2xy + y^2

x^2+2xy+y^2

It's x^2+2xy+y^2..

(x + y)(x + y) = x² + xy + xy + y² = x² + 2xy + y²

The second one...

Try (x,y)=(2,3)
then
(x+y)²=(2+3)² =25
and
x²+y²=2²+3²=13 <> 25
but
x²+2xy+y²=13+2*2*3=25

it's x^2+2xy+y^2?.