## anonymous one year ago graph -2x+4y=4 for the domain D: (-8,-4,0,4,8)

1. anonymous

@pooja195 @satellite73 @MathMath101 @peachpi

2. anonymous

@ganeshie8 @Hero

3. anonymous

@triciaal

4. anonymous

@freckles

5. freckles

well we need to find first what the corresponding y values are for the listed x values... so if x=-8 then y=? use the equation -2x+4y=4 then you will ask yourself if x=-4 then y=? and so on... once we get all the points we just plot then done

6. anonymous

so we finding y now

7. freckles

have you found y for when x=-8 yet?

8. anonymous

y equals 2

9. freckles

$-2x+4y=4 \\ \text{ so we have } x=-8 \\ -2(-8)+4y=4 \\ 16+4y=4 \\ 4y=4-16 \\ 4y=-12 \\ y=\frac{-12}{4}=-3$ are you sure?

10. freckles

because when I plug in -8 for x I get -3 for y

11. anonymous

o sorry

12. freckles

so we will plot (-8,-3) on our little graph paper now you go to the next number in the domain and plug in -4 for x to find what y is when x is -4

13. anonymous

1

14. freckles

close I got y=-1 $-2(-4)+4y=4 \\ 8+4y=4 \\ 4y=4-8 \\ 4y=-4 \\ y=-1$

15. freckles

so we will plot (-4,-1) on our graph also by the way instead of solving for y each time we can do it one time and just plug into that equation instead: $-2x+4y=4 \\ \text{ add } 2x \text{ on both sides } 4y=2x+4 \\ \text{ divide both sides by 4} \\ y=\frac{2x+4}{4} \\ \text{ divide \top and bottom by 2 } \\ y=\frac{x+2}{2}$

16. freckles

ok plug in the next x value

17. freckles

which is 0

18. anonymous

1

19. freckles

right so we will also plot (0,1)

20. freckles

just two more number to plug in

21. freckles

so much fun :p

22. freckles

just to summary what we have so far: $(-8,-3) \\ (-4,-1) \\ (0,1) \\ (4,?) \\ (8,?)$

23. freckles

$(-8,-3) \\ (-4,-1) \\ (0,1) \\ (4,?) \\ (8,?) \\ y=\frac{x+2}{2} \\ (-8,-3) \\ (-4,-1) \\ (0,1) \\ (4,\frac{4+2}{2}) \\ (8, \frac{8+2}{2})$ simplify those bottom two

24. freckles

then plot all 5 coordinates and you are done

25. anonymous

-4

26. freckles

(4+2)/2=?

27. freckles

and (8+2)/2=?

28. anonymous

3

29. anonymous

5

30. freckles

right! $(-8,-3) \\ (-4,-1) \\ (0,1) \\ (4,?) \\ (8,?) \\ y=\frac{x+2}{2} \\ (-8,-3) \\ (-4,-1) \\ (0,1) \\ (4,\frac{4+2}{2}) =(4,3)\\ (8, \frac{8+2}{2}) =(8,5)$

31. freckles

can you plot the points: (-8,-3) (-4,-1) (4,3) (8,5)

32. freckles

oops and (0,1)

33. freckles

I will plot one point if you are unsure how to plot

34. freckles

(-8,-3) look at the first number which is -8 since the number is negative that means we will go left of the origin (the center aka (0,0) ) we will count 8 units to the left of the origin ... the the number which is -3 since the number is negative that means we will go down from the origin we will count down 3 units from the origin the type graphing we are doing is called rectangular ... |dw:1440643068749:dw|

35. freckles

see why the type of graphing is called rectangular you see a rectangle right?

36. freckles

but anyways the rectangle isn't (-8,-3) where those two legs of the rectangle meet that point I drew is where (-8,-3) is

37. anonymous

ok i get it now thank you @freckles

38. freckles

cool stuff :)