Respuesta :
Step1:Multiply each term in the parentheses by y.
Step2: calculate the product

Answer:
[tex] {(x + y)}^{2} - 1[/tex]
Step-by-step explanation:
[tex] {x}^{2} + y(y - 2x) - 1[/tex]
[tex] {x}^{2} + {y}^{2} - 2xy - 1[/tex]
Using the identity (a - b)^2 here ,
[tex] {(x + y)}^{2} - 1[/tex]