Plans for a bridge are drawn on a coordinate grid. One girder of the bridge lies on the y=-9x-9. A perpendicular brace passes through the point (-1,7). Write an equation of the line that contains the brace. Which one is it from the ones below?

A. y-1=-1/9(x+7)
B. x-7=-9(y+1)
C. y-7=1/9(x+1)
D. y-7=-9(x+1)

Question

Plans for a bridge are drawn on a coordinate grid. One girder of the bridge lies on the y=-9x-9. A perpendicular brace passes through the point (-1,7). Write an equation of the line that contains the brace. Which one is it from the ones below?

A. y-1=-1/9(x+7)
B. x-7=-9(y+1)
C. y-7=1/9(x+1)
D. y-7=-9(x+1)

anonymous · Answer

The perpendicular brace has a negative reciprocal slope of the line y = -9x - 9. This line has a slope of -9, so the perpendicular brace has a slope of +1/9.
So now, you have to write the equation of the line whose slope is 1/9 and passes through the point (-1,7). I assume you can do that.

anonymous · Answer

yes I can thank you. :) @Easyaspi314

anonymous · Answer

is it B ?? @Easyaspi314

anonymous · Answer

cuz I did on paper and that seems like the answer

anonymous · Answer

I didnt work it out. Just carefully write that equation.

anonymous · Answer

oh ok, thats ok, but thanks anyways :)

anonymous · Answer

@Easyaspi314