Question

Write the equation of a line in standard form that passes through (-2, 5) and is perpendicular to

the line x – 2y = 8.

Answer 1

Explanation:

x - 2y = 8

Write this in y = mx +b form

- 2y = -x + 8

Divide the equation by (-2)

`(-2y)/(-2)=(-x)/(-2)+(8)/(-2)\\\\\\y =(1)/(2)x-4`

Slope = 1/2

The slope of the perpendicular line = -1/m

`=(-1)/((1)/(2))=1*(-2)/(1) = -2`

m = -2 , ( -2 , 5)

Equation: y = mx +b

Plug in m = -2 ,x = -2 and y =5

5 = (-2)*(-2) + b

5 = 4 + b

5 - 4 = b

b = 1

Equation of the line:

y = mx +b

y = -2x + 1