Question

ex 2 vă rog dau coroană​

Answer 1

$a) {(x + y)}^{2} = (x + y)(x + y) = {x}^{2} + xy + xy + {y}^{2} = {x}^{2} + 2xy + {y}^{2}$

$b) {(x - y)}^{2} = (x - y)(x - y) = {x}^{2} - xy - xy + {y}^{2} = {x}^{2} - 2xy + {y}^{2}$

Answer 2

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