Let $f : \mathbb{R}^2 \to \mathbb{R}$ be defined by $f( \langle x, y \rangle ) = -6x-8y$. Is $f$ a linear transformation?

1. $f( \langle x_1, y_1 \rangle + \langle x_2, y_2 \rangle ) =$ . (Enter $x_1$ as $\verb+x1+$, etc.)
   $f( \langle x_1, y_1 \rangle) + f(\langle x_2, y_2 \rangle) =$ $+$ .
   Does $f(\langle x_1, y_1 \rangle + \langle x_2, y_2 \rangle) = f(\langle x_1, y_1 \rangle) + f(\langle x_2, y_2 \rangle)$ for all $\langle x_1, y_1 \rangle, \langle x_2, y_2 \rangle \in \mathbb{R}^2$? choose Yes, they are equal No, they are not equal
   
   
2. $f(c \langle x, y \rangle) =$ .
   $c(f(\langle x, y \rangle)) =$ $\Big($ $\Big)$.
   Does $f(c\langle x, y \rangle) = c(f(\langle x, y \rangle))$ for all $c \in \mathbb{R}$ and all $\langle x, y \rangle \in \mathbb{R}^2$? choose Yes, they are equal No, they are not equal
   
   
3. Is $f$ a linear transformation? choose f is a linear transformation f is not a linear transformation