Question

Find the equation of the line shown

Answer 1

y=-2x+9

Explanation:

From looking at the line you can already tell that the slope is going to be negative, and the y-intercept is going to be 9, since that's where y is when x is 0. You can see that when x is one, y is 7. When x is 2, y is 5. And when x is 3, y is 3.

So:

0: 9

1:7

2:5

3:3

And the difference of y over the difference of x is the slope

-2/1=-2

So the slope is -2

Therefore, putting the equation together makes:

y=-2x+9

Hope this helps!

Answer 2

Explanation:

at 3=3

at 0=9

at 4=1

`y = ax + b`

`1 = 4a + b \\ 3 = 3a + b \\ 2 = - a \\ a = - 2 \\ 1 = - 4 * 2 + b \\ b = 1 + 8 = 9 \\ y = - 2x + 9`