Write an equation of the line that passes through (7,10)(7,10) and is perpendicular to the line y=12x−9y=12x−9.

Question

Find if the line is perpendicular

Answer 1

If y=12x-9 the slope is 12, so the slope of the perpendicular is -1/12.

The equation of the perpendicular looks like y=-x/12+c where c is a constant to be found by plugging in the coords of the point: 10=-7/12+c. So c=10+7/12=127/12 and y=(127-x)/12 or 12y=127-x.