SOLUTION: how do solve by graphing: x+y=-1 3x-y=-7

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Question 32901This question is from textbook elementary algebra
: how do solve by graphing: x+y=-1
3x-y=-7
This question is from textbook elementary algebra

Answer by xcentaur(357)   (Show Source): You can put this solution on YOUR website!
x+y=-1......[1]
3x-y=-7.....[2]


Take the first equation,substitute x=0,-1,1,2,-2 and so on, and calculate y
you will have all these values of x and y as pairs
x=0,y=-1
x=-1,y=0
x=1,y=-2
and so on
plot these on the graph as (x,y)=(0,-1),(-1,0),(1,-2) etc
Then draw a straight line through the points,connecting them


Repeat for the second equation


The lines will meet at a particular point.From the graph paper,look up the co-ordinates of the point,and there you have your solution. It should work out to (x,y)=(-2,1)


Hope this helps,
xC

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