Question

graph -2x+4y=4 for the domain D: (-8,-4,0,4,8)

Answer 1

@pooja195 @satellite73 @MathMath101 @peachpi

Answer 2

@ganeshie8 @Hero

Answer 3

@triciaal

Answer 4

@freckles

Answer 5

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

Answer 6

so we finding y now

Answer 7

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

Answer 8

y equals 2

Answer 9

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

Answer 10

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

Answer 11

o sorry

Answer 12

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

Answer 13

1

Answer 14

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

Answer 15

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:
\[-2x+4y=4 \\ \text{ add } 2x \text{ on both sides } 4y=2x+4 \\ \text{ divide both sides by 4} \\ y=\frac{2x+4}{4} \\ \text{ divide \top and bottom by 2 } \\ y=\frac{x+2}{2}\]

Answer 16

ok plug in the next x value

Answer 17

which is 0

Answer 18

1

Answer 19

right
so we will also plot (0,1)

Answer 20

just two more number to plug in

Answer 21

so much fun :p

Answer 22

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

Answer 23

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

Answer 24

then plot all 5 coordinates and you are done

Answer 25

-4

Answer 26

(4+2)/2=?

Answer 27

and (8+2)/2=?

Answer 28

3

Answer 29

5

Answer 30

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

Answer 31

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

Answer 32

oops and (0,1)

Answer 33

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

Answer 34

(-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 ...