Question

Choose the equation of the line passing through the point (1, -5) and perpendicular to y =1/5x - 10.
A:y = 5x + 10
B: y = 5x
C:y = -5x - 10
D: y = -5x

Answer 1

HELP!

Answer 2

The line equation is y=kx+b, the lines are perpendicular, so k1*k2=-1, where k1=1/5, k2 is unknown. Solve for k2: k2=-5. So the line we are looking for is y=-5x+b. We know line is passing through the point (1,-5), which means -5=-5+b => b=0. The answer is D

Answer 3

Thank you!

Answer 4

From the given line, you can find its slope.
Once you have the slope of the given line, you can find the slope of a perpendicular.
Once you know the slope of the perpendicular, write
y = mx + b, where m is the slope of the perpendicular.
Plug in the given point (1, -5) and solve for b.