Question

consider the line y= 2/3x-0. Find the equation of the line that is parallel to this line and passes through the point (8, 4).

Answer 1

Point-slope form of a line: we need a point (x₀,y₀) and the slope "m".
y-y₀=m(x-x₀)

slope intercept form :
y=m+b

m=slope

If the line is parallel to y=2/3 x-0, the line will have the same slope, therefore the slope will be: 2/3.

Data:
(8,4)
m=2/3

y-y₀=m(x-x₀)
y-4=2/3(x-8)
y-4=2/3 x-16/3
y=2/3 x-16/3+4
y=2/3 x-4/3  (slope intercept form)

Answer: The equation of the line would be: y=2/3 x-4/3.


if we have the next slope "m",then the perendicular slope will be:
m´=-1/m

We have this equation: y=2/3 x+0; the slope is: m=2/3.

The perpendicular slope will be: m`=-1/(2/3)=-3/2

And the equation of the perpendicular line to : y=2/3 x+0, given the point (8,4) will be:

y-y₀=m(x-x₀)
y-4=-3/2 (x-8)
y-4=-3/2 x+12
y=-3/2x + 12+4
y=-3/2x+16

answer: the perpendicular line to y=2/3 x+0 , given the point (8,4) will be:
y=-3/2 x+16