Answer:
[tex]y = 2(0.5) {}^{x} [/tex]
Step-by-step explanation:
Use the general formula of exponential equation
[tex]y = ab {}^{x} [/tex]
Plug 0,2 into the function
[tex] - 2 = ab {}^{0} [/tex]
[tex] - 2 = a \times 1[/tex]
[tex]a = - 2[/tex]
[tex]y = - 2b {}^{x} [/tex]
[tex] - 4 = - 2b {}^{ - 1} [/tex]
[tex]2 = b {}^{ - 1} [/tex]
[tex] {2}^{ \frac{ 1}{ - 1} } [/tex]
[tex]2 {}^{ - 1} = 0.5[/tex]
B=0.5
[tex]y = 2(0.5) {}^{x} [/tex]