The given line is
The line passes through (5, -1),
Perpendicular lines have opposite slopes, so we use the following equation to find the new slope knowing that the slope of the given line is -2.
Now, we use the slope, the point, and the point-slope formula to find the equation.
Therefore, the equation of the new perpendicular line is
So, she's not correct, she didn't substitute the correct x and y values.
The right answer is C.