Is the line description for x+3y=1 slanted downwards?

Yes it is (and instead of saying downwards, it's clearer to say that as the x value increases, y decrease). 
If you chance the formula into y = mx +b form, you get y = -1/3 + 1/3, and since m, or the slope, is negative, the line will decrease from right to left across the graph

Photo math will give you the step by step answer : )

Number 40 is a rational number glad i could