Question

Devon made the scatter plot to track his bank balance over time.

What is the equation of the graphed linear model?

y = x +
http://static.k12.com/calms_media/media/1549000_1549500/1549113/1/ab694ddd1f04d55c25077d014a1e7eeb0dc4774a/MS_IMC-141014-181217.jpg

Answer 1

40/-235

Answer 2

Oh, my bad..that's (0, 250)..

Answer 3

Take the two points:

(0, 250) and (14, 40)

Plug them in the slope formula:

\(m = \dfrac{y_2-y_1}{x_2-x_1}\)

\(m = \dfrac{40-250}{14-0}\)

Simplify

Answer 4

-210/14

Answer 5

Yep, divide that

Answer 6

-15

Answer 7

Yes, so that's our slope, now we plug this along with one of the points in point-slope form.

\(y - y_1 = m(x - x_1)\)

Where \(y_1\) is the y-value of the point, \(x_1\) is the x-value of the point, and \(m\) is the slope.

So we have:

\(y - 40 = -15(x - 14)\)

Distribute -15 into the parenthesis:

\(y - 40 = -15x + 210\)

Add 40 to both sides, what's 210 + 40?

Answer 8

250

Answer 9

Yes, so we have:

\(y = -15x + 250\)

Answer 10

-15 goes in the first blank, 250 goes in the 2nd