How do you write an equation in slope-intercept form of the line through point P(-10,1) with slope -5?

2 Answers
May 25, 2015

Since we're given the slope and a point, let's start with point slope form.

The point slope form is:

#y - y_0 = m(x - x_0)# where #m# is the slope and #(x_0, y_0)# is a point through which the line passes.

In our case #m=-5# and #(x_0, y_0) = (-10, 1)#, so we can write:

#y - 1 = -5(x - (-10)) = -5(x + 10)#

Slope intercept form is:

#y = mx+c# where #m# is the slope and #c# the intercept.

To rearrange in slope intercept form, add #1# to both sides to get:

#y = -5(x+10)+1#

#= -5x-50+1#

#= -5x - 49#

This is pretty much slope intercept form with slope #m=-5# and intercept #c = -49#.

If we are really picky, we might write:

#y = -5x + -49#

May 25, 2015

The equation in slope-intercept form is #y=-5x-49#.

Slope-intercept form: #y=mx+b#, where #m# is the slope and #b# is the y-intercept.

Substitute the known values into the equation, then solve for #b#.

#y=1 #m#=-5#
#x=-10#

#y=mx+b# =

#1=-5(-10)+b# =

#1=50+b#

#-49=b#

#y=-5x-49#