(0,-1),(1,2),(2,5),(3,8)

Question

function rule

 

Answer 1

Hi Jacob;

We need to establish the slope of the line.

Slope is defined as change-of-y divided by change-of-x, also known as rise-over-run...

m=(y-y₁)/(x-x₁)

Let's select two points.  How about the first and last?...

m=(-1-8)/(0-3)=-9/-3=3

A negative number divided by a negative number has a positive result.

Let's double-check our results.  Let's take the first and second coordinate...

m=(2-5)/(1-2)=-3/-1=3

The y-intercept is the value of y when x=0.  It is provided as (0,-1).

Slope-intercept formula is...

y=mx+b

m is the slope, b is the y-intercept...

y=3x-1