Write an equation of a line perpendicular to y=1/2x-5 in slope-intercept form that passes through the point (2, -7).

4 answers

slope of new line must be -2

so y =-2x + b
plug in the given point (2,-7)
-7 = -2(2) + b
-3 = b

y = -2x - 3
The key to perpendicular lines is that the slopes will multiply together to get negative one. Since your original slope is 0.5, your new slope will be -2. Passing through your stated points, the point-slope equation of the line will be:

y-(y1)=m(x-(x1))

plug in your slope & points..

y+7=2(x-2) , simplified, this gives you

y=2x-11

Hope this helps!
I forgot the - in the above answer that I gave. It should really be

y+7=-2(x-2)

y=-2x-3
Wow thanks! It is correct! :D