There are two sets of x,y points on a straight line in a two-variable graph with y on the vertical axis and x?

Question

There are two sets of x,y points on a straight line in a two-variable graph with y on the vertical axis and x on the horizontal axis, If one set of points was (0,6) and the other set (6,18), the linear equation for the line would be????
y = 6 + .5x

y = 6x

y = 6 + 2x

y = 6 + 1x

Answer 1

The equation of a line given two points:
There are many ways to do this, but in your case the easiest is:

Since you have the point (0,6), you have the y intercept (where your equation crosses the y axis). The easiest way to write the equation would be to use the slope intercept form y=mx+b where m is the slope and b is the y intercept. The point (0,6) tells you b = 6, since y = 6.

Now you need m, the slope. To find slope, remember rise over run, or change in y over change in x.

Your y's are 18 and 6 (from the points you gave, in (x,y) form), so your change in y is 18 - 6 = 12.

your x's are 6 and 0, so 6 - 0 = 6. Rise over run, or change in y / change in x gives you 12 / 6, which simplifies to 2.

Your equation would then be y = 2x+6, or, in terms of your above choices, y = 6 + 2x.

Answer 2

y = 2 x + 6

Answer 3

3) y=6+2x

you can sub the values into the general equation of a line y=mx+b and get b=6 from (0,6) and 18=6x+6 from (6,18) so m=2.

Answer 4

The slope of the line is 12/6 = 2
Thus y = 2x + b
So 6 = 0 +b --> b = 6
Thus answer is y = 2x+6

Answer 5

You only need two points to determine a line. The easiest ones to get can be obtained by setting one of the variables to zero, and solving for the other one. In the above example, setting x=0 yields the point (0, -15), and setting y=0 yields (3,0). Hope this helps.

Answer 6

y= 6+2x

Answer 7

The second answer is right:
y=6+2x