Question

Which of the following statements best describes the effect of replacing the graph of y = f(x) with the graph of y = f(x) + 20?

The graph of y = f(x) will shift left 20 units.
The graph of y = f(x) will shift down 20 units.
The graph of y = f(x) will shift up 20 units.
The graph of y = f(x) will shift right 20 units.

Answer 1

Choose the equation below that represents the line that passes through the point (−2, −1) and has a slope of 5.

y − 1 = 5(x − 2)
y + 1 = 5(x + 2)
y + 2 = 5(x + 1)
y − 2 = 5(x − 1)

and this one

Answer 2

On the first one, all you are doing is adding 20 to f(x), which just adds 20 to y. So, the graph shifts up 20.

Use the point-slope form of the line:

y - (-1) = 5(x - (-2))
or
y + 1 = 5(x+2)