EXPLANATION
Given that the slope is equal to m=-2 and we have the (6,1), we can write the point-slope form and then turn it into a standard form as shown as follows:

Replacing terms:

Applying the distributive property:

Adding +1 to both sides:
y = -2x + 12 + 1
Adding numbers:
y = -2x + 13
Adding +2x to both sides:
y + 2x = 13
Rearranging terms:
2x + y = 13
As the standard form of a line is Ax + By = C, our standard form equation is as follows:
2x + y = 13