Greetings!
"10-3" can also be written as:
1) -3+10
2)10+(-3)
Hope this helps.
-Benjamin
You didn't show us much of the page with the question on it,
so we can't be sure of exactly what you're working on in math.
If you're working with things like squares and rectangles, then
'L' and 'W' are often used to represent the Length and Width of
shapes drawn on paper, or even Length and Width of 3D objects
like blocks or boxes.
Take any 2 points through which the line on graph passes,
(0,-1) =(x₁,y₁)
& (2,-4)=(x₂,y₂)
slope=(y₂-y₁)/(x₂-x₁)
=[-4-(-1)]/(2-0)
=-3/2