"Give the slope and the y intercept of the line" by what object, not clear? The slope can be determined if you express y: 3 x + 10 y = 5 => 10y = 5 - 3x => y = [5 - 3x]/10 =>
y = -0.3x + 0.5. arctan (-0.3) = -arctan (0.3)
[input]-atan(0.3)[/input]
Well, as is unclear your question about what by what is intercepted as it is, let's assume that the line intercepts Ox, we have to find x, i.e. let's assume that there such point A exists that the graph is inter-crossing Ox at the point A (x ; 0). Inserting 0 instead of y, we'll get 0 = -0.3x + 0.5 => 0.3x = 0.5 => x = 0.5/0.3 = 5/3. If we wish to find the coordinate y of the graph inter-crossing Oy, then we assume that there such point B exits, that B (0 ; y) => y = -0.3*0 + 0.5 = 0.5. Did I answer your question?
The graph is below
[input]plot(-0.3x + 0.5, x=-5..5, -5..5)[/input]
+259 
