Answer: D) 2 units down
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Work Shown:
f(x) = 3x+8
g(x) = 3x+6
g(x) = 3x+6+0 .... adding on 0 doesn't change anything
g(x) = 3x+6+2-2 ... replace 0 with 2-2
g(x) = (3x+6+2)-2
g(x) = (3x+8)-2
g(x) = f(x)-2 ... replace 3x+8 with f(x)
The last line shows that g(x) is the result of shifting f(x) down 2 units.
Recall that y = f(x). When we say f(x)-2, we mean y-2. So we subtract 2 from every y coordinate, which is why the f(x) graph moves down 2 units.