How to subtract functions

Now Playing:Subtract functions – Example 1a

Determine the Difference of Two Functions Algebraically
If $f(x)= 5x^3-x+6$
and
$g(x)=4x-8,$
Determine:
1. $(f-g)(x)$
  
  0/5
2. $(g-f)(x)$
  
  0/5
3. $(g-f)(-2)$
  evaluate in two different ways
  
  0/5
Determine the Difference of Two Functions Graphically
Given the graphs of functions $f(x)$
and $g(x)$
1. sketch: $(g-f)(x)$
2. evaluate:
  i)
  $(g-f)(-3)$
  ii)
  $(g-f)(0)$
  iii) $(g-f)(4)$
Determine the Difference of Two Functions Point-by-Point
The graph of $y=f(x)$
includes the points (2,5),(4,15),(7,30)
The graph of $y=g(x)$
includes the points (2,6),(3,16),(4,30)
If f and g are defined for all real values of x , then which of the
following points must lie on the graph of $y=(f-g)(x)?$
1. $(0,-1)$
2. $(0,1)$
3. $(2,-1)$
4. $(3,30)$