To find the equation,we can use the two-point form:

Where m is the slope.
First,we need to find the slope:

We can then find the formula by putting any point in it.
Put (0,5) into the formula:
5-y = -2(0-x)
-y = 2x-5
y = -2x+5
Therefore the answer is y = -2x + 5.
Hope it helps!