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How Would You Graph The Equation Y=2x+4?

3 Answers

Ellie Hoe Profile
Ellie Hoe answered
In the equation y = 2x+4 just put the value of x = 0,1,2,3,4.... In order to get the value of y like this

If x = 0 then

y = 2x+4
y = 2(0)+4
y = 0+4
y = 4

(x,y) = (0,4)

if x = 1 then
y = 2x+4
y = 2(1)+4
y = 2+4
y = 6

(x,y) = (1,6)

if x = 2 then
y = 2x+4
y = 2(2)+4
y = 4+4
y = 8

(x,y) = (2,8)

if x = 3 then
y = 2x+4
y = 2(3)+4
y = 6+4
y = 10

(x,y) = (3,10)

if x = 4 then
y = 2x+4
y = 2(4)+4
y = 8+4
y = 12

(x,y) = (4,12)

x | y
0 | 4
1 | 6
2 | 8
3 | 10
4 | 12
  .
  .
  .
and so on

Now you have x and y coordinates, so it is easy to make the graph. The value of x and y shows that the line lies in 1st quadrant only if the value of x is Positive.
Anonymous Profile
Anonymous answered
Start with a value of 0 for x.  It's obvious right away the y value at this coordinate will be 4.  Plot (0,4).

Now set y = 0 and solve for x.  

0 = 2x + 4
x = -4/2
   = -2

So plot a value of (-2,0).  

Try another point for verification.

Let's use x = 1.

y = 2(1) + 4

y = 6

So plot a value of (1, 6)

The three points should be on a line.  If it doesn't line up, there is a problem solving for one of the points, or your equation wasn't a linear relationship.  But in this case, it was linear, so they should all fall on a line.

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