Question

The expansion of (2x-y)${}^2$ is:

• A. 4x${}^2$ - 4xy + y${}^2$
• B. 4x${}^2$ - 4xy + y${}^2$
• C. 4x${}^2$ - 4xy + y${}^2$
• D. 4x${}^2$ - 4xy + 64y${}^2$

Answer 1

The correct option is A 4x${}^2$ - 4xy + y${}^2$

Using the identity (a-b)${}^2$ = a${}^2$ - 2ab + b${}^2$
(2x-y)${}^2$ = (2x)${}^2$ - 2(2x)(y) + y${}^2$ = 4x${}^2$ - 4xy + y${}^2$.