How do you find the slope and intercept to graph #y-2=-1/2(x+3)#?

1 Answer
Apr 17, 2018

The slope is #-1/2# and the y-intercept is #(0,1/2)#

Explanation:

This equation is in point-slope form which is:

#y-y_1= m (x-x_1)#

m is the slope and #(x_1,y_1)# can be any point on the line. So in this case, the point we are given is #(-3,2)#

Since there's a #-1/2# in the m's place for this equation, we automatically know that the slope is #-1/2# (since m stands for slope).

To find the y-intercept, you'll have to simplify the equation.
Start with distributing the #-1/2#

Given: #y-2= -1/2 (x+3)#

1) Distribute : #y-2= -1/2x-3/2#
2) Add 2 to both sides: #y= -1/2x-3/2 +2#
#y= -1/2x+1/2# <-- equation in standard form

This is the standard form of the equation. From the equation we can see #1/2# is the y-intercept (plug in 0 for x as y-intercepts always have 0 as the x coordinate) , so your final answer is #(0,1/2)#!

I'm not sure if you wanted to find what the x-intercept is as well but I'll tell you how to do that too.

x-intercepts always have a 0 in the y coordinate so make the equation equal to 0/plug in 0 for y.

1) #y= -1/2x+1/2#

2) #0= -1/2x+1/2# <-- make the equation equal 0 (plug in 0 for y)

3) #-1/2= -1/2x# <-- subtract both sides by #1/2#

4) #-1/2-: (-1/2)= x# <-- divide both sides by #-1/2#

5) #-1/2 *(-2/1)= x#

6)#x=1#

therefore your answer is #(1,0)# for the x-intercept.