SOLUTION: 6) Graph the equation and identify the y-intercept y+x=-9 the y-intercept is

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Question 146899: 6) Graph the equation and identify the y-intercept
y+x=-9
the y-intercept is
Answer by jim_thompson5910(21667) About Me  (Show Source):
You can put this solution on YOUR website!
y%2Bx=-9 Start with the given equation


y=-9-x Subtract +x from both sides


y=-x-9 Rearrange the equation



Looking at y=-x-9 we can see that the equation is in slope-intercept form y=mx%2Bb where the slope is m=-1 and the y-intercept is b=-9


Since b=-9 this tells us that the y-intercept is .Remember the y-intercept is the point where the graph intersects with the y-axis

So we have one point

drawing%28500%2C500%2C-10%2C10%2C-15%2C5%2C%0D%0A++grid%281%29%2C%0D%0A++blue%28circle%280%2C-9%2C.1%29%29%2C%0D%0A++blue%28circle%280%2C-9%2C.12%29%29%2C%0D%0A++blue%28circle%280%2C-9%2C.15%29%29%0D%0A%29


Now since the slope is comprised of the "rise" over the "run" this means
slope=rise%2Frun

Also, because the slope is -1, this means:

rise%2Frun=-1%2F1


which shows us that the rise is -1 and the run is 1. This means that to go from point to point, we can go down 1 and over 1



So starting at , go down 1 unit
drawing%28500%2C500%2C-10%2C10%2C-15%2C5%2C%0D%0A++grid%281%29%2C%0D%0A++blue%28circle%280%2C-9%2C.1%29%29%2C%0D%0A++blue%28circle%280%2C-9%2C.12%29%29%2C%0D%0A++blue%28circle%280%2C-9%2C.15%29%29%2C%0D%0A++blue%28arc%280%2C-9%2B%28-1%2F2%29%2C2%2C-1%2C90%2C270%29%29%0D%0A%29

and to the right 1 unit to get to the next point
drawing%28500%2C500%2C-10%2C10%2C-15%2C5%2C%0D%0A++grid%281%29%2C%0D%0A++blue%28circle%280%2C-9%2C.1%29%29%2C%0D%0A++blue%28circle%280%2C-9%2C.12%29%29%2C%0D%0A++blue%28circle%280%2C-9%2C.15%29%29%2C%0D%0A++blue%28circle%281%2C-10%2C.15%2C1.5%29%29%2C%0D%0A++blue%28circle%281%2C-10%2C.1%2C1.5%29%29%2C%0D%0A++blue%28arc%280%2C-9%2B%28-1%2F2%29%2C2%2C-1%2C90%2C270%29%29%2C%0D%0A++blue%28arc%28%281%2F2%29%2C-10%2C1%2C2%2C+0%2C180%29%29%0D%0A%29


Now draw a line through these points to graph y=-x-9

drawing%28500%2C500%2C-10%2C10%2C-15%2C5%2C%0D%0A++grid%281%29%2C%0D%0A++graph%28500%2C500%2C-10%2C10%2C-15%2C5%2C-x-9%29%2C%0D%0A++blue%28circle%280%2C-9%2C.1%29%29%2C%0D%0A++blue%28circle%280%2C-9%2C.12%29%29%2C%0D%0A++blue%28circle%280%2C-9%2C.15%29%29%2C%0D%0A++blue%28circle%281%2C-10%2C.15%2C1.5%29%29%2C%0D%0A++blue%28circle%281%2C-10%2C.1%2C1.5%29%29%2C%0D%0A++blue%28arc%280%2C-9%2B%28-1%2F2%29%2C2%2C-1%2C90%2C270%29%29%2C%0D%0A++blue%28arc%28%281%2F2%29%2C-10%2C1%2C2%2C+0%2C180%29%29%0D%0A%29 So this is the graph of y=-x-9 through the points and