It's called the "dividend". A dividend is a number to be divided by another number. The 3 is the divisor, a number by which another number is to be divided.
The slope between the points (x1,y1) and (x2,y2) is
slope=(y2-y1)/(x2-x1)
(0,6) and (5,-4)
x1=0
y1=6
x2=5
y2=-4
slope=(-4-6)/(5-0)=-10/5=-2
slope=-2
<span>x-y=11 2x+y=19
x=11+y
2(11+y)+y=19
22+2y+y=19
3y=-3
y=-1
x=11-1=10</span>
The only math term I can think of is geometry and it means when a solid is cut through parallel to the base.
EDIT: After further research since it was all I could think of. This is the only math term for what you are looking for.