Again, complicated... look down.?

Question

Here is more data. I need to find the EQUATION for this graph.

i'll write in in table form.

x= 0 | 6 | 18 | 24 | 30 |
y= 4 | 6 | 8 | 10 | 12 |


remember, the equation

Answer 1

You need to know how to work these out for yourself (we're not going to sit the exam for you, or do any maths that may come up in your post-school life).

Straight lines have an equation of the form y = mx + c
where m is the slope and c is the y-intercept (that's the value of y where the line crosses the y-axis).

The slope of a straight line is given by (increase in y value) divided by (increase in x value). That gives you the value of m.

You can then use one of the points (pairs of values in your table) to work out c.

So what do you need to do?
First, take any pair of points from the table, perhaps (0,4) and (6,6).
Work out the slope (note that a decrease is a negative increase, so in this case you should expect the slope to be negative).
Then use either of the points to work out the y-intercept.
Now you know both m and c, you have the equation as y=mx+c.
Finally, check that the other points in the table are on the line.

Answer 2

Hey, SV, how do you know the relation is linear? Or, rather, what makes you think the relation is linear?