You start from the $yy$-axis intercept (here $y=0y=0$) and go $11$ to the right and $33$ upwards.

The slope is therefore: $m={\displaystyle \frac{3}{1}}=3m\; =\; \backslash dfrac\{3\}\{1\}=3$

You start from the $yy$-axis intercept (here $y=3y=3$) and go $11$ to the right and $33$ downwards.

The slope is therefore: $m={\displaystyle \frac{-3}{1}}=-3m=\backslash dfrac\{-3\}\{1\}=-3$

You start from the $yy$-axis intercept (here $y=-3y=-3$) and go $22$ to the right and $33$ upwards.

The slope is therefore: $m={\displaystyle \frac{3}{2}}=\mathrm{1,5}m=\backslash dfrac\{3\}\{2\}=1\{,\}5$

You start from the $yy$-axis intercept (here $y=4y=4$) and go $11$ to the right and $11$ downwards.

The slope is therefore: $m={\displaystyle \frac{-1}{1}}=-1m=\backslash dfrac\{-1\}\{1\}=-1$

You start from the $yy$-axis intercept (here $y=-3y=-3$) and go $11$ to the right and $22$ upwards.

The slope is therefore: $m={\displaystyle \frac{2}{1}}=2m=\backslash dfrac\{2\}\{1\}=2$