Respuesta :
For this case we have by definition, if two lines are perpendicular then the product of their slopes is -1.
[tex]m_ {1} * m_ {2} = - 1[/tex]
We have the following equation:
[tex]28x-7y = 9[/tex]
Rewriting we have:
[tex]28x-9 = 7y\\y = \frac {28x-9} {7}\\y = 4x- \frac {9} {7}[/tex]
The slope of this line is 4.
We found [tex]m_ {2}:[/tex]
[tex]m_ {2} = \frac {-1} {m_ {1}}\\m_ {2} = \frac {-1} {4} = - \frac {1} {4}[/tex]
The new line is of the form:
[tex]y = - \frac {1} {4} x + b[/tex]
We substitute the given point to find the cut point "b":
[tex]1 = - \frac {1} {4} (4) + b\\1 = -1 + b\\b = 2[/tex]
Finally, the equation is:
[tex]y = - \frac {1} {4} x + 2[/tex]
Answer:
[tex]y = - \frac {1} {4} x + 2[/tex]