SOLUTION: Could someone help me with a few system of equations problems please? These ones are to be solved by the graphing method,and I have to show how I got them when I take the test in

Algebra ->  Matrices-and-determiminant -> SOLUTION: Could someone help me with a few system of equations problems please? These ones are to be solved by the graphing method,and I have to show how I got them when I take the test in       Log On


   

Question 145192: Could someone help me with a few system of equations problems please? These ones are to be solved by the graphing method,and I have to show how I got them when I take the test in the future,So if you could show me step by step that would be great.
1) -x + y = -1
x + y = 3

2) 3x + y = -6
x + y = -4
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
I'll do the first one to get you started





Start with the given system of equations:

-x%2By=-1
x%2By=3




In order to graph these equations, we need to solve for y for each equation.



So let's solve for y on the first equation

-x%2By=-1 Start with the given equation


y=-1%2Bx Add +x to both sides


y=%2Bx-1 Rearrange the equation


Now lets graph y=x-1 (note: if you need help with graphing, check out this solver)


+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+x-1%29+ Graph of y=x-1



So let's solve for y on the second equation

x%2By=3 Start with the given equation


y=3-x Subtract +x from both sides


y=-x%2B3 Rearrange the equation



Now lets add the graph of y=-x%2B3 to our first plot to get:

+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+x-1%2C-x%2B3%29+ Graph of y=x-1(red) and y=-x%2B3(green)

From the graph, we can see that the two lines intersect at the point (2,1)