Answer
(a) Direct variation.
(b) Inverse variation.
Work Step by Step
(a) The given equation is
$\frac{y_1}{x_1}=\frac{y_2}{x_2}$
Let each side of the equation is equal to $k$ constant.
$\frac{y_1}{x_1}=k$
$y_1=kx_1$
Hence, the given equation is direct variation.
(b) The given equation is
$y_1x_1=y_2x_2$
Let each side of the equation is equal to $k$ constant.
$y_1x_1=k$
$y_1=\frac{k}{x_1}$
Hence, the given equation is inverse variation.
