Question

okay, so i have a math packet to do and one of the sections is to graph each system of equations and state its solution.

1.) x+2y=-7
2x-3y=o

i dont know how to do this.

Answer 1

For the top equation, you may first let x=0 and solve for y:
x=0 ==> 2y=-7 ==> y=-7/2 ==> (0,-7/2)
Then repeat for y=0:
y=0 ==> x=-7 ==> (-7,0)
The you may use these two pints to graph the line.
(cont)

Answer 2

For the bottom equation you might want to solve for y to get into the slope-intercept form since the x-int and y-int are the same:
y=2x/3
Then, you can pick any convenient value of x. A multiple of 3 is good here:
x=6 ==> y=2(6)/3=4 ==> (6,4)
The other point to use on this line is (0,0).
Now you can graph the second line.
(cont)

Answer 3

The intersection of the two lines is the solution. Beware it takes some precision to get the answer this way. Use graph paper if you have it.

I will attach the graph if you give me a minute.
(cont)

Answer 4

okay

Answer 5

The solution is (-3,-2) and the graph is attached. let me know if you have any questions.

Answer 6

i just dont understand this AT ALL. i have such a hard time.

Answer 7

You know that line have the form ax+y=c where a,b,c are numbers? When you have two of them, you have a "system" the solution is where they intersect.

Answer 8

alright.. i can understand that.

Answer 9

And you know that it takes two points to "fix" or locate a line in the plane. So what I did was find two points for a each line, and graph them using a software that I have so that I could show you, but it is easily done by hand. Then I looked for the point of intersection which turned out to be (-3,-2).