find the angle for the line
3x-15y+7
do i divid them all by -15 so that i get y alone?
-0.2x+y-0.46
y=-0.2x-0.46
this seems wrong somehow
The line has an equation, not an expression.
$\displaystyle 3x-15y+7=0\Rightarrow y=\frac{1}{5}x+\frac{7}{15}$.
The slope is $\displaystyle m=\frac{1}{5}$.
On the other hand, the slope is the tangent of the angle between the line and the positive x-axis.
So, $\displaystyle m=\tan\alpha=\frac{1}{5}\Rightarrow\alpha=\arctan\ frac{1}{5}$.