Let's take a look at $(x + y)^2$ and $x^2 + y^2$. While Beeker believes that these two expressions are equal for all real numbers $x$ and $y,$ Clod believes they are not! Let's get to the bottom of this!

a) Evaluate $(x + y)^2$ and $x^2 + y^2$ for $x = 7$ and $y = 11.$

b) For which values of $x$ and $y$ does $(x + y)^2$ equal $x^2 + y^2?$ For which values of $x$ and $y$ does $(x + y)^2$ not equal $x^2 + y^2?$