SOLUTION: Can you help me I cannot get this and I am afraid to ask the teacher again. I need to graph the following 4 equations on my graph paper. (1) 2x+y=9 (2) -x-y = -8 (3) -

Algebra ->  Graphs -> SOLUTION: Can you help me I cannot get this and I am afraid to ask the teacher again. I need to graph the following 4 equations on my graph paper. (1) 2x+y=9 (2) -x-y = -8 (3) -       Log On


   

Question 24885: Can you help me I cannot get this and I am afraid to ask the teacher again.
I need to graph the following 4 equations on my graph paper.
(1) 2x+y=9
(2) -x-y = -8
(3) - 3x + 4y = 2
(4) -2x -y = -3
Can you please explain in detail each step and if possible also plot them on a graph.
Thank you.
Answer by elima(1433) About Me  (Show Source):
You can put this solution on YOUR website!
I'm sorry to hear you afraid to ask your teacher, don't ever be afraid to ask us.
First step would be to but each equation in slope-intercept form;
y=mx+b
m=slope
b=y-intercept
(1) 2x+y=9
subtract 2x from each side ;
y=9-2x
but this in the slope -intercept form;
y=-2x+9
slope=-2%2F1
y-intercept=9
the y-intercept is your strating point on the graph, it is;
(0,9)
So you plot that point on the graph and with the slope of -2/1 you count the units and plot the next point.
so from (0,9) you go 2 units down and 1 unit over to the right. Thepoint you land on should be (1,7), and then plot one more point, then you draw your line
graph+%28300%2C300%2C+-3%2C3%2C-3%2C11%2C+-%282%2F1%29x%2B9%29
(2) -x-y = -8
For this one add x to each side;
-y=-8+x
y=8-x
Correct form;
y=-x+8
slope=-1%2F1
y-intercept=8
graph+%28300%2C300%2C+-3%2C3%2C-3%2C11%2C+-x%2B8%29
(3) - 3x + 4y = 2
4y=2+3x
y=2%2F4+3x
y=3x+1%2F4
slope=3%2F1
y-intercept=1%2F4
graph+%28300%2C300%2C+-3%2C3%2C-3%2C5%2C+3x%2B1%2F4%29
(4) -2x -y = -3
-y=-3+2x
-y=2x-3
y=-2x+3
slope=-2%2F1x
y-intercept=3
graph+%28300%2C300%2C+-3%2C3%2C-3%2C5%2C+-%282%2F1%29x%2B3%29
Hope you understand, don't be afraid to ask when you have problems.
=)