The slope of the line is calculated using
y2 - y1 / x2 - x1
Substituting the given values
-8 - 27 / 5 - 0 = -7
The rate of change or the slope is -7
And the initial value is the value of y when x is 0. From the first coordinates, the initial value is 27.
Step-by-step explanation:
x + 8a = 25 + ax - 7a
x = 5
5 + 8a = 25 + 5a - 7a
5 + 8a = 25 - 2a
5 + 10a = 25
10a = 20
a = 2