Question

What is the rate of change and initial value for the linear relation that includes the points shown in the table?

ху
1 20
3 10
5 0
7 -10
Initial value: 20, rate of change: 10
Initial value: 30, rate of change: 10
Initial value: 25, rate of change: -5
Initial value: 20, rate of change: -10

Answer 1

Initial Value: 25, Rate of change -5.

First. Lets find the rate of change.

y2-y1/x2-x1 = m

We have A(1,20) B(3,10)

10-20/3-1=-5

m=-5(Rate of change)

Now let's find the initial value using slope-point form.

y-y₁=m(x-x₁)

y-20=-5(x-1)

=-5x+5+20

=-5x+25

The initial value is the value of y when the value of x is equal to 0. (Also the Y-Intercept)

Initial Value = -5(0)+25

=25