How to graph 2y-10x=20

First, put it into slope/intercept form so you can see what you've got.

"Slope/intercept form" is      y = everything else  .

So that means you have to take the equation you have and "solve it for 'y' ".

2y - 10x = 20

Add  10x  to each side:        2y = 10x + 20

Divide each side by  2 :        y  =  5x  +  10

There it is. 
Now that you have it in that form, you can just look at it and see that the
slope of the line on the graph is  5, and the line crosses the y-axis at 10.

And that's exactly the information you need to graph it.  On your graph,
mark a little dot on the y-axis at  10, and draw a line through that dot
with a slope of  5.