Sounds as tho' all three lines are parallel. Is that correct?
If so, all three lines have the same slope!
What is the slope of 5y=2x-20 ? Solving for y, y = (2/5)x - 4
The slope is (2/5).
Now find the equation of the line with slope (2/5) that passes thru (10,-8).
It is y - [-8] = (2/5)(x - 10).
We can simplify this, with the result y + 8 = (2/5)x - 4. This, in turn, can be simplified to y + 8 = 2x/5 - 4, or y = 2x/5 - 12. Mult. all terms by 5 to eliminate the fraction:
5y = 2x - 60
Note how this has the exact same form as the given 5y = 2x - 20, EXCEPT that the constant at the end is different.
5y = 2x - 60 and 5y = 2x - 20 are parallel lines with the same slope but different y-intercepts.
