Question

Solve the system by graphing.

-2x= 2y - 4
2x - y = -5

Answer 1

I am so not good at graphing. I just don't get this.

Answer 2

x is your input
y is your output

First
isolate the y for both of these equations

Answer 3

once you have done that I will tell you the next step

Answer 4

ok

Answer 5

by isolate I mean move y to one side of the equation and the rest of the junk to the other side of the equation

Answer 6

If you get stuck with the algebra I can help you just show me where you get stuck

Answer 7

ok let me see if Im doing this right. when I isolate y for the first equation of -2x = 2y - 4, would it be 2y = -2x + 4?

Answer 8

yes that is the first step

2y = -2x + 4

now to isolate the y further we need to eliminate the 2, we can do this by dividing both sides of the equation by 2, remember that 2/2 = 1 and y*1 = y

so

2y/2 = -2x/2 + 4/2
1(y) = (-2x + 4)/2
y = (-2x + 4)/2

Answer 9

Now just do the same for the next equation and I will tell you what to do next

Answer 10

ok

Answer 11

2x - y = -5

convert to: y = 2x + 5?

Answer 12

looks good :)

Answer 13

ok so now I have y = -2x + 2
and y = 2x + 5
the x's cancel out making y = 7?

Answer 14

ok so we have:

y = 2x + 5

y = -2x/2 + 4/2

both equations are linear

so first find the x and y intercepts

you find the x-intercept by setting y = 0
so you get point (x,0)

to find the y-intercept you set x = 0
so you get a point (0,y)

next just graph a variety of points, by inserting values into x and seeing what you get out as y

so for example graph

-10, -5, -4, -2, 0, 2, 4, 5, 10

what this problem is asking you is where these two equations intersect

Answer 15

okay now Im lost lol Do I graph just points on x. Graphing is where I am completely confused

Answer 16

using this axis, each time you insert a value into x you get a value y, this gives you a point on the graph

(x,y) plot the points and connect them with a line

Answer 17

so for the second equation

y = -x + 2

I'm going to find the intercepts

to find the x-intercept I set y=0, giving me a point (x,0)

0 = -x + 2
-2 = -x
2 = x

so I have a x-intercept of (2,0)

now I'm going to find the y-intercept by setting x = 0 giving me a point (0,y)

y = -0 + 2
y = 2

so I have a y-intercept of (0,2)



I'm going to insert -10 into the x value to give me point (-10,y)

y = -(-10) + 2
y = 10 + 2
y = 12

so I have point

(-10,12)

I'm going to insert -5 into the x value to give me point (-5,y)

y = -(-5) + 2
y = 5 + 2
y = 7

so I have a point

(-5, 7)

Now I graph the points I have and connect them with a line

Answer 18

ok