Question

A line passes through the points (15,−13) and (16,−11). Hollis writes the equation y+13=(x−15) to represent the line. Which answer correctly analyzes his equation? His equation is incorrect. He incorrectly wrote the slope and switched the values of the coordinates. He should have written y−15=2(x+13). His equation is incorrect. He switched the values of the coordinates. He should have written y−15=x+13. His equation is correct. He correctly included and placed all parts for the point-slope form of the equation of the line. His equation is incorrect. He switched the signs of the coordinates. He should have written y−13=x+15. His equation is incorrect. He incorrectly wrote the slope and switched the signs of the coordinates. He should have written y−13=2(x+15). His equation is incorrect. He incorrectly wrote the slope in his equation. He should have written y+13=2(x−15).

Answer 1

The equation formula is y - y1 = m(x-x1)

Using the first point for x1, y1:

Y +13 = m(x-15)

M is the slope which is the change in y over the change in x:

M = -11–13 / 16-15 = 2/1 = 2

The equation becomes y +13 =2(x+15)

The answer is:

He incorrectly wrote the slope in his equation. He should have written y+13=2(x−15).