Posted by Lucas on Wednesday, March 23, 2011 at 8:52pm.
y = x - 4
to get y, just plug in each given value of x,,
if x = 4,
y = 4 - 4 = 0
if x = 0,
y = 0 - 4 = -4
if x = -4,
y = -4 - 4 = -8
if x = -6,
y = -6 - 4 = -10
hope this helps~ :)
Describe the relationship between x and y.
x: +5,+2,0,-3
y: 3,0,-2,-5
by observation, we see that a given value of x is 2 greater than its corresponding value of y,,
since it's fixed (or the difference between the values is constant), we say that the relationship between them is linear.
getting the equation, we first find the slope of the line, represented by m:
m = (y2-y1)/(x2-x1)
where x1 and y1 are the x- and y-coordinate of a point on the line, and x2 and y2 is another, different point on the line
say we choose the points (5,3) and (2,0) as (x1, y1) and (x2, y2) respectively:
m = (y2-y1)/(x2-x1)
m = (0-3)/(2-5)
m = -3/-3 = 1
now we get the equation using slope intercept form given by:
y - y1 = m(x - x1)
let's choose (5,3) as our (x1, y1),, substituting:
y - 3 = 1(x - 5)
y - 3 = x - 5
rearranging to standard form (note: standard for is Ax + By = C, where A,B and C are constants):
x - y = 2
..which is true based on our observation.
hope this helps~ :)