Answer:
The slope is 1.
Step-by-step explanation:
A first order function has the following format
[tex]y = ax + b[/tex]
In which a is the slope
(6, -12).
This means that when [tex]x = 6, y = -12[/tex]
So
[tex]y = ax + b[/tex]
[tex]-12 = 6a + b[/tex]
(15. -3)
This means that when [tex]x = 15, y = -3[/tex]
So
[tex]y = ax + b[/tex]
[tex]-3 = 15a + b[/tex]
We have to solve the following system of equations:
[tex]-12 = 6a + b[/tex]
[tex]-3 = 15a + b[/tex]
We have to find a
In the second equation i will write as:
[tex]b = -3 - 15a[/tex]
Replacing in the first
[tex]-12 = 6a + b[/tex]
[tex]-12 = 6a - 3 - 15a[/tex]
[tex]-9 = -9a[/tex]
[tex]9a = 9[/tex]
[tex]a = \frac{9}{9}[/tex]
[tex]a = 1[/tex]
The slope is 1.
