What is the equation of the line that has a slope of -1 and goes through point (0, 5)?

To answer the question above, know that one of the way of writing the equation of the line is through the point - slope form which is generally expressed as,
 
                                       y - y1 = m(x - x1) 

where m is the slope and x1 and y1 are the abscissa and ordinate of the point, respectively.

Substituting the given data to the equation above,
 
                                      y - 5 = -1(x -0)

By simplification we get an answer of

                                        y = -x + 5