What is the equation of the line with slope m= 1/3 that passes through (-7/15,-5/24) ?

2 Answers
Feb 14, 2016

y=x/3-19/360

Explanation:

y=mx+c

-5/24=1/3 * (-7/15) + c

c=-5/24+1/3*7/15

c=-19/360

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Let the desired equation be

y=mx+c
To find out c, insert values of the m, x and y coordinates from the given point.
-5/24=(1/3)*(-7/15)+c

=>c=-5/24+1/3*7/15

=>c=-5/24+7/45
=>c=(-5*15+7*8)/360
=>c=(-75+56)/360
=>c=-19/360

Feb 14, 2016

y=1/3x-19/360

Explanation:

The first answer is correct, but I would like to provide an alternative solution using the point-slope form.

Point-slope form:

Given a point (x_0,y_0) and a slope m, the equation of the line is:

" "y-y_0=m(x-x_0)

You just have to substitute everything.

Solution

[1]" "y-y_0=m(x-x_0)

[2]" "y+5/24=1/3(x+7/15)

[3]" "y+5/24=1/3x+7/45

[4]" "y=1/3x+7/45-5/24

[5]" "y=1/3x+7/45-5/24

[6]" "y=1/3x+(56-75)/360

[7]" "color(blue)(y=1/3x-19/360)