Question

Write an equation of the line that is perpendicular to y = 1/2

x + 3 and passes through the point (10, -5).

A) y = -2x + 15

B) y = 2x - 15

C) y = -2x - 5

D) y = - 1/2x

Answer 1

the equation of the line that is perpendicular to y = 1/2x + 3 and passes through the point (10, -5)

= -5 = -2x + 15

Explanation:

Write an equation of the line that is perpendicular to y = 1/2x + 3 and passes through the point (10, -5).

Using the slope intercept equation,

y = mx +c

m = slope = 1/2

For two lines to be perpendicular, the product of their slopes is -1

Let the slope of the other line be m2

m1×m2 =-1

1/2×m2 = -1

m2 = -1/(1/2) = -2

Slope of line = -2

For points (10, -5), x = 10, y =-5

-5 = -2× 10 +c

-5 = -20+ c

c = -5+20= 15

the equation of the line that is perpendicular to y = 1/2x + 3 and passes through the point (10, -5)

-5 = -2x + 15