Answer:
For the question on the right, I assume b is the exponential factor, or growth factor.
Step-by-step explanation:
Linear:
[tex]Y=aX + b\\(X, Y) = (0, 15) => b = 15\\(X,Y) = (1, 12) => a = -3\\Y = -3X + 15[/tex]
You can find the equation by using two points and the equation for a line.
Exponential:
[tex]Y = a^{bX+c}\\(X, Y) = (0, 81) => a^{c} = 81 => a^{c} = 3^{4} => a=3, c=4\\(X, Y) = (1, 27) => a^{b+c} = 27 => a^{b}a^{c} = 27 => a^{b} = \frac{27}{81} = \frac{1}{3} => b=-1\\Y = 3^{-X+4}[/tex]
